- 2/3 cup cake flour
- 1/3 cup cocoa powder
- Pinch of baking soda
- 4 Tbsp unsalted butter
- 6 large eggs
- 3/4 cup granulated sugar
- Pinch of salt
- 2 tsp vanilla extract
- 2 cups (16 oz) fresh or frozen blackberries
- 2 Tbsp fresh lemon juice
- 1 cup granulated sugar
- 2 Tbsp cornstarch
- 4 egg yolks
- 2 eggs
- 4 Tbsp unsalted butter cut into 6 pieces
- 1 1/2 cups heavy cream
- 6 fresh mint leaf sprigs
- 2 Tbsp granulated sugar
- Grated good-quality chocolate curls for garnish
To make the cake, preheat oven to 350°. Spray a jelly roll (10 ½” x 15 ½”) pan with baking spray with flour. Line with a piece of parchment paper and spray again.
In a bowl, sift flour, cocoa, and baking soda. Set aside.
In a small saucepan over low heat or microwave, melt butter. Set aside in a warm place.
In a bowl set over but not touching simmering water in a saucepan, add eggs and sugar and whisk until sugar has dissolved. Remove from heat, and beat on high speed until mixture is thick and pale and has tripled in volume. Reduce speed to medium, add vanilla, and beat 2-3 minutes more.
In two additions, sift flour mixture over egg mixture, folding in gently with a spatula. While folding in last addition, pour melted butter over batter and fold in.
Pour batter evenly in pan. Tap pan on counter to remove air bubbles. Bake until a cake tester comes out clean, 15-20 minutes. Let rest on a wire rack until cool enough to handle. Turn out onto a cutting board, remove parchment, and cut into 2” pieces.
To make the curd, wash fresh blackberries and add to a bowl of a food processor with blade attachment. Puree until smooth. Pour puree through a fine-mesh strainer and use back of a spoon to push berries through strainer.
In a saucepan over medium-low heat, add blackberry puree, lemon juice, and sugar and stir to combine. Depending on sweetness, add more sugar, as desired. Add cornstarch, eggs, and yolks and cook, stirring constantly with a whisk, until mixture thickens and resembles pudding. Remove from heat, add butter, and whisk until blended.
If needed, pass curd through a strainer into another bowl. Press a piece of plastic wrap directly onto surface of curd and refrigerate for at least 1 hour.
To make the cream, in a saucepan over medium heat, add cream and mint and heat until wisps of steam appear, about 8 minutes. Remove from heat and let mint steep while cream cools, about 10 minutes.
Remove mint from cream and transfer cream to a bowl and, using a hand mixer, beat cream until soft peaks form. Add sugar and continue to beat until stiff peaks form.
To assemble, add half of chocolate cake pieces to bottom of trifle bowl. Spoon 1 cup of blackberry curd over cake. Place dollops of mint cream over curd. Repeat with remaining cake, curd, and cream. Garnish with chocolate curls. Cover with plastic wrap and chill in the refrigerator until ready to serve.