Martha Stewart Belgian Chocolate Birthday Cake

Martha Stewart Belgian chocolate birthday cake is an easy-to-follow showstopper made with toasted hazelnuts, Dutch-process cocoa and a glossy ganache, ready in 2 hours 30 minutes. Save this make-ahead chocolate birthday cake for parties, Christmas dessert tables or holiday dinners, because the cake bakes days early.

Whip half of the ganache over an ice bath until it turns lighter and spreadable, then coat the chilled cake with it. Pour the remaining ganache over a firm base layer, or it will slide off and leave bare patches.

Martha grinds toasted hazelnuts with sugar and folds them right into the flour, so the crumb tastes nutty all the way through. She also blooms the cocoa in boiling water first, which deepens the chocolate flavor far beyond what dry cocoa alone gives.

Martha Stewart Belgian Chocolate Birthday Cake

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Course: DessertCuisine: American, BelgianDifficulty: Medium

Servings

10

servings

Prep time

45

minutes

Cooking time

1

hour 

10

minutes

Calories

650

kcal

A dense, moist hazelnut-chocolate crumb sits under a smooth poured ganache and a pile of bittersweet curls. Whipping half the ganache first gives the pour a clean base, so the glaze sets glossy.

Ingredients

• 4 ounces hazelnuts
  

• 13 1/3 tablespoons unsalted butter (1 ⅔ sticks), softened
  

• 2/3 cup Dutch-process cocoa powder
  

• 6 tablespoons granulated sugar
  

• 1 2/3 cup all-purpose flour
  

• 1 1/2 teaspoons baking soda
  

• 1/4 teaspoon table salt
  

• 2/3 cup boiling water
  

• 1 3/4 cups packed dark-brown sugar
  

• 4 large eggs, at room temperature
  

• 1 1/3 cups buttermilk, at room temperature
  

• 2 1/2 teaspoons pure vanilla extract
  

• Quick Chocolate Ganache
  

• Candied Hazelnuts and Chocolate Curls
  

Directions

• Toast the hazelnuts: Preheat the oven to 350°F, spread 4 ounces hazelnuts on a baking sheet and bake about 12 minutes until fragrant. Rub them in a clean kitchen towel to loosen the skins, then butter a 9-by-3-inch springform pan well and coat it with cocoa.
• Grind the nuts: Pulse the nuts with 6 tablespoons granulated sugar in a food processor until fine but not pasty. Then stir them into a large bowl with 1 2/3 cups flour, 1 1/2 teaspoons baking soda and 1/4 teaspoon salt.
• Bloom the cocoa: Whisk 2/3 cup Dutch-process cocoa powder with 2/3 cup boiling water in a heat-proof bowl until smooth. It thickens as it cools, so don't worry if it looks stiff.
• Cream the butter: Beat the softened butter and 1 3/4 cups packed dark-brown sugar on high for 3 to 4 minutes until lightened and fluffy. Then add the 4 eggs one at a time, mixing until each is blended.
• Mix and bake the batter: Stir the buttermilk and vanilla into the cocoa mixture. With the mixer on low, add half the dry ingredients, then the cocoa mixture, then the rest of the dry mix, stopping once it's just incorporated.
• Cool the cake: Scrape the batter into the pan, smooth the top and bake 1 hour to 1 hour 10 minutes, until a tester comes out clean. Cool 10 minutes in the pan, unmold, then cool completely on a 9-inch cardboard round.
• Whip the ganache: Put half the Quick Chocolate Ganache in a bowl set over a larger bowl of ice water. Whip it with a whisk until lighter and spreadable, moving the bowl in and out of the ice bath as needed.
• Coat and chill: Spread the whipped ganache over the top and sides of the cooled cake, then chill it. Stir the remaining ganache every 5 minutes until thickened and cool.
• Pour and garnish: Set the cake on a wire rack over parchment and ladle the ganache over the top in circles, letting it run down the sides. Let it stand at room temperature until set, then add the candied hazelnuts and chocolate curls.

Tools for this recipe

• Nordic Ware 9-inch springform pan, Cuisinart 14-cup food processor, KitchenAid Artisan 5-quart stand mixer, Nielsen-Massey Madagascar Bourbon vanilla extract, 8 oz. As an Amazon Associate I earn from qualifying purchases.

FAQs

Can I bake the cake ahead of time?

Yes, the cake can be baked up to three days ahead. Wrap it well and keep it at room temperature, then glaze it the day you serve it so the ganache stays shiny.

How far ahead can I make the garnishes?

You can prepare both the candied hazelnuts and the chocolate curls up to three days in advance. Keep each in its own airtight container so the nuts stay crunchy and the curls don't soften.

Do I have to use Dutch-process cocoa?

Dutch-process gives the deepest, smoothest chocolate flavor, so I'd stick with it. If you only have natural cocoa, the cake will taste a bit sharper and may rise differently since the baking soda balance changes.

How do I get the hazelnut skins off easily?

Toast the nuts until fragrant, about 12 minutes, then wrap them in a clean kitchen towel while still warm. Rub them hard and most of the skins flake right off, so a few stubborn bits left over are fine.

Why did my ganache slide off the cake?

The most common cause is skipping the whipped base layer or pouring ganache that is still too warm. Chill the cake after the first coat and stir the remaining ganache until it thickens, so it clings instead of running.