Chocolate Gateau (Chocolate Cake) ガトーショコラ

Moist and rich Chocolate Gateau recipe is a classic dessert found in cafes and pastry shops across Japan. Topped with strawberries and fresh whipped cream, this decadent cake is a beautiful and elegant sweet treat to make at home for any festive occasion.

It has always been my goal to expand our recipes for Japanese sweets and pastries on Just One Cookbook. However, baking is not my strong suit, so I brought in a Japanese pastry assistant, Haruka, to the team so that we could share authentic treats with our readers.

Today’s recipe, Chocolate Gateau or gâteau au chocolat (ガトーショコラ), is one of the first recipes we worked on together. With the holidays fast approaching, we wanted to share something you can bring to family gatherings or make ahead for a party that you’re hosting. And this chocolate cake recipe is THE ONE you need!

Firstly, the cake itself is impossibly rich and moist, with a well-rounded, truffle-like flavor. Next, it strikes the perfect balance of sweetness—sweet but not overly so. Finally, the topping! The whipped cream and strawberries truly take this cake to the next level, offering a fresh contrast to the overall enjoyment. ‘Kanpeki 完璧,’ as we would describe it in Japanese!

What is Chocolate Gateau?

A chocolate gâteau, also known as gâteau au chocolat (ガトーショコラ), is a classic French cake made with eggs, butter, sugar, chocolate, cocoa powder, and flour. This luscious dessert is rich, moist, dense, and intensely flavorful. It can be found everywhere, from cafes and pastry shops in Japan.

Some people say that the chocolate gâteau tastes like a chocolate brownie. It’s true that they both have an intensely deep and concentrated chocolate flavor. However, there are some key differences.

While brownies are rich and heavy, the gâteau is rich without the heaviness. The chocolate gâteau has a uniform cake crumb that’s structured yet tender. It‘s somewhat dense yet lighter and more airy than a brownie, which is fudgy and extremely dense.

Western sweets in Japan are heavily influenced by European (typically French) sweets rather than American sweets, and they are not as sweet as American desserts.

The recipe requires simple but high-quality ingredients, including chocolate chips (for baking purposes) and cocoa powder, to make a gateau in which the chocolate flavors shine. The overall flavor is indulgent enough that you don’t even need any chocolate frosting on top.

Ingredients for Gateau Chocolat

• Cake flour – You can use all-purpose flour, but cake flour (less gluten) is preferred.
• Dutch-process cocoa powder
• Salt
• Eggs
• Unsalted butter
• Chocolate chips – Use good-quality baking chips! I like using 2 parts semi-sweet chocolate (46% cacao) and 1 part extra dark chocolate (63% cacao) for our preference.
• Granulated sugar
• Milk – You also can use heavy cream for a richer taste.
• Cake decoration – Strawberries or raspberries, confectioners’ sugar, heavy whipping cream, and sugar.

Jump to Recipe

How to Make Chocolate Gateau

1. Prepare the chocolate mixture. Melt the chocolate chips and butter in a double boiler.
2. Prepare the yolk mixture. Whisk egg yolks and sugar until it becomes a thick texture and pale in color.
3. Combine the chocolate and yolk mixture.
4. Beat the egg whites. Fold the egg whites and dry ingredients into the chocolate mixture.
5. Pour the batter and bake. Let cool completely and refrigerate overnight.
6. Invert the cake and decorate the cake before serving.

Tips for Preparing the Ingredients

1. Measure the ingredients with a kitchen scale. I highly recommend using a kitchen scale to measure the ingredients, as we did for this recipe. However, I wanted to ensure that this recipe is easy to measure by volume for those who prefer using cups. If you choose to use cups, measure your flour and cocoa powder by “fluffing and sprinkling.” Otherwise, you will scoop and compact too much flour or cocoa powder into the measuring cup and end up with a dry, dense cake. Once you get used to using a kitchen scale, you’ll appreciate its convenience. No more washing multiple measuring cups!
2. Keep your eggs at room temperature. This is a small yet important step. Set a reminder to take out the eggs from the fridge 30–60 minutes before you start prepping so they come to room temperature naturally.

3. Sift the flour and cocoa powder. Don’t take shortcuts. Sifting dry ingredients ahead of time helps incorporate them into the wet ingredients and avoid lumps in the batter.
4. Line the 8-inch (20-cm) round cake pan with parchment paper. I’ll show you my trick later in the post. Also, use a light-colored cake pan for the best outcome. Avoid using a dark-colored pan because it will absorb heat faster and more intensely and your cake will bake more quickly, possibly overbake, and may even burn. If you must use a dark pan, reduce the oven temperature by 25°F (15°C) and check for doneness 10 minutes sooner than the instructions indicate.

How to Melt the Chocolate in a Double Boiler

A double boiler is a heat-proof bowl set over a larger saucepan filled with 2 inches (5 cm) of barely simmering water. It allows for indirect, gentle heat when warming up temperature-sensitive ingredients, like chocolate, that require a delicate touch.

1. Never expose melted chocolate to water! Any water will cause the chocolate to seize. Make sure the bowl fits tightly on top of the saucepan because escaping steam could cause your melted chocolate to seize up.
2. For bittersweet or semisweet chocolate, remove from the heat when the chocolate mixture reaches 122°F (50°C) and keep it at 104ºF–122ºF (40–50ºC) to prevent the chocolate from hardening. DO NOT let your chocolate mixture cool because it will become extremely difficult to combine with other ingredients.

Tips for Making the Batter

1. Make sure to use room-temperature egg yolks so that they don’t harden the chocolate mixture when combined. Whisk the yolks and sugar until the mixture becomes thick and pale in color.
2. Gradually incorporate all the warm chocolate mixture into the egg yolk mixture.

3. Beat the egg whites until they form very soft peaks. When lifting the beaten egg whites with the whisk, they should be soft enough to drop a few times and then stop; they should not be runny. This process is a bit different from making Chiffon Cake and Japanese Cheesecake, so be careful not to overbeat the egg whites.
4. Use a scooping motion with your whisk when adding the egg whites and dry ingredients to the batter.

5. Add all the dry ingredients when you see “a nice marble effect.” Stop mixing when you notice a little bit of dry ingredients are still left.
6. When using a silicone spatula, fold in the mixture from the bottom of the bowl.

Baking Tips

1. Check your oven’s actual temperature. I know my oven doesn’t reach the desired temperature even though it beeps and says it’s done preheating. Know your oven’s characteristics! Some ovens heat up too quickly, while others struggle to reach the optimal temperature. I put a thermometer inside the oven to determine the actual temperature.
2. Pour the batter into the pan all at once and in one spot to both minimize air pockets and smooth the top of the batter.

3. Drop the cake pan a few times on the countertop before putting it into the oven. This releases the air bubbles trapped in the cake batter.
4. Use a skewer to check the cake’s doneness. Don’t assume that your cake is done just because the timer is up. If you change the size of your cake pan, it‘s especially important to check with a skewer.

5. After baking, drop the cake pan once on the countertop to release hot air trapped inside the cake. This prevents the cake from shrinking.
6. Let the cake cool in the pan completely. We highly recommend leaving it in the cake pan overnight in the refrigerator for better texture and flavor.

Serving Tips

1. Invert the cake onto the palm of your hand to release it from the pan, then quickly flip it back over onto a plate or cake stand.
2. I recommend keeping the cake at room temperature for 10–15 minutes before serving. The cake will not be as dense after leaving it out for some time. You can also warm it up if that’s what you prefer.

Cake Decoration Tips

Because the Chocolate Gateau is rich and focuses on quality chocolate flavor, I prefer not to add too much decoration to the cake. Here, I give two simple decoration options.

1. Whipped Cream + Strawberries – This has a wow factor, yet it’s simple to decorate. Make whipped cream with heavy whipping cream and sugar until it’s a spreadable consistency. Then, decorate with sliced strawberries in the shape of a flower. My quick tip is to create irregular patterns for a natural look.
2. Confectioners’ Sugar + Raspberries – Simply dust the confectioners’ sugar on top of the cake and decorate it with raspberries.

How to Line the Round Baking Pan

I used to find lining the baking pan with parchment paper a daunting process. Plus, I didn’t want to buy precut sheets of parchment circles for a cake pan that I don’t frequently use.

Then, I learned this lining technique from my friend, which I thought was super smart. It does take some time, but I appreciate the fact that I can use the entire sheet of precut parchment paper without wasting any parts of it. Thinking that you might be like me, I wanted to share this technique here.

1. To measure the pan’s bottom, place an 8-inch (20-cm) round cake pan on a sheet of parchment paper and trace around the outside with a pen.
2. For the pan’s sides, use the extra paper next to the circle you traced. Fold it in half lengthwise and make a sharp crease to mark the center line.

3. With a pair of scissors, cut out the circle along the traced line. I like to cut just inside the line so the circle is the right size. Set it aside.
4. Next, cut off the rectangular sheet from the paper if it’s still attached, as I did here.

5. With the rectangular sheet folded in half lengthwise, fold up the long edges together to form a flap about ½ inch (1.3 cm) wide. Make a sharp crease to mark the flap, then unfold it.
6. While holding the edges together, cut straight notches up to the crease mark every ½ inch (1.3 cm) across the entire length of the flaps.

7. Unfold the rectangular sheet and cut it in half along the center line crease. Now, you have two strips, each with a notched flap along one long edge.
8. Line the side of the pan with the strips, placing the flap sides down with the notches lying flat on the pan’s bottom. The folded part should fit neatly where the pan’s side meets the bottom. Overlap the short edges of the strips.

9. Line the bottom of the pan with the parchment paper circle, placing it on top of the notched flaps.
10. There’s no need to grease the pan or parchment paper.

How to Adjust to Different Pan Sizes

I use an 8-inch (20-cm) round cake pan in my recipe. However, you can adapt my recipe if you want to use a larger or smaller cake pan.

For a 9-inch (23-cm) round cake pan:

• use 6 large eggs;
• use 120% (6/5) of the other ingredients; and
• bake for a longer time (check with a skewer).

For a 6-inch (15-cm) round cake pan:

• use 3 large eggs;
• use 60% (3/5) of the other ingredients; and
• bake for a shorter time (check with a skewer).

FAQs

What kind of chocolate is best?

We can’t make the best chocolate cake without using the highest quality chocolate you can. I recommend getting confectionery chocolate, combining semi-sweet (46% cacao) and extra dark (63% cacao) in this recipe. For a chocolate gateau, it’s best to use chocolate with 55–70% cacao.

Can I substitute Dutch-process cocoa powder with natural cocoa powder?

Your cake will be lighter in color since natural cocoa is inherently lighter than Dutch-process. Due to the acidity of natural cocoa, you may notice a subtle tanginess or a slightly bitter taste.

You can find Dutch-process cocoa powder at many gourmet food stores, like Whole Foods and Williams-Sonoma. You can also buy the same one I use on Amazon.

How can I add espresso powder to this recipe?

Espresso powder can be added to the recipe for an intensified, complex, and deep chocolate flavor. Since it’s very concentrated, you only need half to one teaspoon (otherwise, too much coffee flavor) while the chocolate is melting.

Baking Tools You Need

• My favorite kitchen scale
• 8-inch round cake pan from William Sonoma
• Pre-cut parchment paper sheet
• Thermapen (instant-read thermometer)
• Fine-mesh sieve
• Balloon whisk
• KitchenAid Artisan Series 5 Quart
• Glass bowls
• Metal bowls

Readers’ Chocolate Gateau Recipes

Chocolate Gateau was the challenge recipe for the JOC Cooking Challenge December 2023. Check out the beautiful chocolate gateau created by JOC readers!

Try Other Delicious Cakes

• Matcha Gateau au Chocolat
• Chocolate Chiffon Cake
• Matcha Marble Pound Cake
• Japanese Cheesecake

Wish to learn more about Japanese cooking? Sign up for our free newsletter to receive cooking tips & recipe updates! And stay in touch with me on Facebook, Pinterest, YouTube, and Instagram.