Chocolate Ice Cream Cake (Triple Chocolate)

A trifecta of chocolate stars in this uniquely constructed frozen dessert: decadent dark chocolate cake, rich white chocolate ganache, and luscious chocolate ice cream. Whether you're a chocolate lover, have a summer birthday, or both, this recipe is for you. Buttermilk helps to keep the cake super moist while a white chocolate ganache offsets the richness of chocolate cake and chocolate ice cream.

Chocolate Cake:
unsalted butter, room temperature, for pans
¾ cup unsweetened Dutch-process cocoa powder
1½ cups all-purpose flour, unbleached
1½ cups sugar
1½ tsp. baking soda
¾ tsp. baking powder
¾ tsp. kosher salt
2 large eggs, room temperature
¾ cup buttermilk, room temperature
3 Tbsp. safflower oil
1 tsp. pure vanilla extract
¾ cup warm water

White Chocolate Ganache:
12 oz white chocolate, chopped
1 cup heavy cream

2 qts chocolate ice cream, softened

To Serve:
lightly sweetened whipped cream
milk chocolate shavings

Preheat oven to 350°F (180°C/160°C fan, Gas Mark 4). Butter a 9" round cake pan (2" deep); line with parchment. Butter parchment, then dust with cocoa, tapping out excess. Repeat process with a 15½x10½" jelly-roll pan.

For the Cakes:
In the bowl of a mixer fitted with the paddle attachment, beat together cocoa, flour, sugar, baking soda, baking powder, and salt on low speed until just combined. Add eggs, buttermilk, oil, and vanilla; beat to combine. Add water; increase speed to medium and beat until smooth, about 3 minutes.

Transfer 1 cup batter to prepared cake pan and remaining batter to prepared jelly-roll pan, spreading both batters evenly with an offset spatula. Bake until set and a tester inserted into centers comes out clean, 12-14 minutes. Transfer pans to wire racks and let cool 15 minutes. Invert cakes from pans; reinvert onto racks and let cool completely.

White Chocolate Ganache:
Place chocolate in a medium bowl. Heat cream in a small saucepan over medium; pour over chocolate. Let stand 3 minutes. Gently stir with a spatula until fully incorporated. Cover and refrigerate until set but still spreadable, about 1 hour. If ganache is too firm, let stand at room temperature or beat with a mixer until softened.

Trim edges of rectangular cake. Top with ganache; spread evenly to edges. Using a ruler, cut cake evenly into quarters; stack on top of one another, gently pressing down to adhere layers. Cover and refrigerate 30 minutes. Using a ruler, cut cake lengthwise into 1" wide strips, then cut each strip in half (they should be about 3½-4" tall).

Transfer 9" cake to a 10" springform pan. Place cake strips around perimeter of cake, flush with edge of pan.

Spread ice cream over cake in pan; cover and freeze overnight. Just before serving, remove cake from freezer; unlatch pan, remove cake, and top with whipped cream and chocolate shavings.

Makes 1 (9") cake.