If you love the combination of chocolate and peanut butter, this cake will make you happy. The recipe is straight out my book Flavorful, and it’s one of my favorites. The chocolate genoise is a simple cake, but it can be a little fickle to make, so do read the instructions carefully. The recipe requires you to clarify some butter, an extra step that is necessary to remove excess water from it, which may cause the cake to sink in the center. As for the glaze, you can cover the whole cake in it, or go for the ‘drip’ look, letting it drip over the sides naturally.
Makes 12 servings
- 7 tablespoons (100 grams) unsalted butter
- ½ cup plus 1 tablespoon (64 grams) sifted cake flour
- ½ cup (38 grams)sifted unsweetened Dutch-processed cocoa powder
- ½ teaspoon salt
- 6 large (300 grams) eggs
- 1 cup (200 grams) granulated sugar
- 1/3 cup (75 grams) clarified butter, hot (from above)
- 1 ¼ teaspoons vanilla paste or extract
White Chocolate-Peanut Butter Mousse:
- 3.5 ounces (100 grams) white chocolate, chopped
- ¾ cup (180 grams) creamy peanut butter (I like Jif)
- 2 ¼ cups (522 grams) heavy cream, divided
- ½ cup (121 grams) whole milk
- 2 tablespoons (28 grams) unsalted butter, softened
- 1/8 teaspoon salt
- 1 teaspoon vanilla paste or extract
Quick Sugared Peanuts:
- 3/4 cup (100 grams) salted roasted peanuts
- 1 1/2 tablespoons (31 grams) light corn syrup
- 1 tablespoon (13 grams) firmly packed light brown sugar
- 6 ounces (170 grams) bittersweet chocolate (60% to 62%), finely chopped
- 3/4 cup (174 grams) heavy cream
- 3 tablespoons (60 grams) light corn syrup
- 1 teaspoon vanilla extract
Clarify the butter:
- Cut the butter into tablespoons and place it in a heavy saucepan over medium heat, partially covered to prevent spattering. When the butter is melted, reduce the heat to low and cook, uncovered, until the solids drop to the bottom of the pan and begin to turn brown.
- Strain the butter through a fine-mesh sieve or cheesecloth-lined strainer.
Make the genoise:
- Position a rack in the center of the oven and preheat the oven to 350˚F. Line the bottom of a 9-inch springform pan with a round of parchment paper (don’t grease the pan or the paper).
- Sift the flour, cocoa and salt together three times; set aside.
- In the bowl of an electric mixer, whisk together the eggs and sugar by hand until well blended. Set the bowl over a saucepan of barely simmering water, making sure that the bottom of the bowl does not touch the water. Heat the egg mixture, stirring constantly with the whisk until it is very warm to the touch and the sugar is dissolved.
- Remove from the heat and transfer the bowl to the mixer stand. Using the whisk attachment, beat on high speed until the egg mixture triples in volume and is very light, about 8 minutes.
- Place the hot clarified butter into a large bowl and stir in the vanilla extract.
- Sift about one-third of the flour mixture over the whipped eggs and, using a rubber spatula, fold it in until almost combined. Sift in the remaining flour mixture in two more additions, again folding in gently. Scoop about 3/4 cup of the batter into the hot butter and stir together until well blended. Pour the butter mixture into the remaining batter and fold it in, being sure it is completely blended. Pour into the prepared pan and smooth the top.
- Bake the cake for 25 to 30 minutes, until the top springs back when lightly touched and it shrinks slightly from the sides of the pan.
- Transfer the pan to a wire cooling rack and let the cake cool completely in the pan.
- Run a thin knife around the inside of the pan to release the cake. Unlatch and remove the side of the pan, invert the cake onto the cooling rack and remove the pan bottom and parchment. Using a long, serrated knife, trim about 1/4 inch off the side of the cake all the way around (this will ensure the mousse will neatly cover the side of the cake when it’s assembled). Cut the cake in half horizontally to form two layers. Clean the springform pan to prepare it for the cake assembly.
Make the mousse:
- Place the white chocolate and peanut butter in a large bowl. In a small saucepan, heat 1/2 cup of the cream and the milk over medium-high heat until scalding. Pour the hot cream mixture over the chocolate and peanut butter and gently whisk until smooth. Add the butter and whisk until melted. Whisk in the salt and vanilla. Set the mixture aside to cool completely.
- Place the remaining 1 3/4 cups cream in the bowl of an electric mixer fitted with the whisk attachment and whip at high speed until soft peaks form. Gently fold the whipped cream into the cooled peanut butter mixture one-third at a time.
Assemble the cake:
- Place one of the cake layers in the bottom of the cleaned springform pan, centering it in the pan. Scrape about half of the peanut butter mousse over the cake and spread it into an even layer with a spatula, letting it fill the gap between the edge of the cake and the side of the pan. Lay the second cake layer on top, centering it. Scrape the remaining mousse over the cake, spreading it into an even layer with a spatula and letting it fill the gap between the cake and the pan. Freeze the cake for at least 1 hour, until firm.
Make the sugared peanuts:
- Preheat the oven to 350°F. Line a baking sheet with a silicone baking mat or lightly oil it with vegetable oil.
- In a medium bowl, stir together the peanuts, corn syrup, and brown sugar. Put the nuts on the prepared baking sheet and use your hands to separate them so that they are not in one big mass. Bake, stirring once or twice during baking, until the nuts are nicely browned, 12 to 15 minutes. Place the baking sheet on a wire rack and let the nuts cool completely. Once cool, break the nuts apart with your fingers and then coarsely chop them.
Make the glaze:
- Place the chocolate in a medium bowl. Heat the cream and corn syrup in a small saucepan over medium-high heat until scalding, stirring occasionally. Pour the hot cream mixture over the chocolate and let it stand for 30 seconds. Gently whisk until smooth. Whisk in the vanilla.
Glaze the cake:
- Run a thin, sharp-bladed knife around the edge of the cake pan, wiping it clean as needed, to release the cake (if necessary, you can run the knife under hot water and dry it beforehand). Unlatch and remove the side of the pan. Use a small offset metal spatula to smooth over any uneven spots on the mousse. Place the cake on a cardboard cake round, if you have one, and then place it on a wire rack over a large piece of parchment or waxed paper to catch any drips of glaze. Pour the glaze onto the center of the top of the cake and use a small offset metal spatula to gently nudge the glaze over the edge of the cake, letting it drip over the sides. Use the spatula to spread the glaze carefully over any uncovered spots on the sides of the cake (or just go for the ‘drip’ look). Sprinkle the nuts over the top of the cake. Let the cake stand at room temperature for at least 30 minutes before serving to allow the mousse to soften. Refrigerate any leftover cake, covered with plastic wrap, for up to 5 days.