Chocolate and Vanilla Pudding Cake

By nlhartman

From Martha Stewart magazine

Ingredients

• Cake:
• Unsalted butter,softened for pan
• 3/4 c Dutch process cocoa powder, plus more for pan
• 1 2/3 cups cake flour(not self rising)
• 1 1/3 cups sugar
• 3/4 t. Baking powder
• 3/4 t. Baking soda
• 1 1/4 t. Kosher salt
• 2 large eggs, room temperature
• 3/4 cup buttermilk, room temperature
• 3/4 cup hot tap water
• 2 t. Pure vanilla extract
• 6 T. Vegetable oil
• Filling:
• 1/3 cup sugar
• 2 T. Cornstarch
• 1 T. Cocoa powder
• 1/4 t. Kosher salt
• 1 1/2 cups whole milk
• 2 large eggs yolks(whites reserved for frosting)
• 1 t. Vanilla extract
• 4 oz milk chocolate, coarse chopped
• 2 T unsalted butter
• Frosting:
• 3 large egg whites
• 3/4 cup. Sugar
• Pinch of salt
• 1 1/2 sticks unsalted butter, softened, cut into tablespoons
• 3 oz white chocolate, chopped coarsely

Preparation

Step 1

Cake:
Preheat oven to 350. Brush the bottom and sides of a 9 x 13 round springform pan with butter; line bottom with parchment paper (cut to fit if not prerounded)and brush with butter. Dust parchment and sides of pan with cocoa, tapping out excess.

Step 2

In a large bowl, whisk together cocoa, flour, sugar, baking powder, baking soda and salt to thoroughly combine. Whisk I eggs, buttermilk, hot water, vanilla and oil. Transfer batter to prepared pan. Bak until top springs back when lightly pressed, 40-45 minutes. Transfer to a wire rack; let cool 20 minutes. Unlatch and remove side of pan; invert cak onto rack, remove parchment, and let cool completely.

Step 3

Filling:
In a sauce pan,whisk together sugar, corn starch, cocoa and salt. Whisk in milk and egg yolks. Bring to a boil over medium- high heat, whisking constantly; boil 1 minute. Remove from heat; whisk in vanilla, chocolate and butter until melted and smooth. Transfer to a heatproof bowl and cover with plastic wrap pressing it directly onto surface of pudding pervert a skin from forming. Let cool about 10 minutes.

Step 4

Meanwhile, trim top of cake flat with a serrated knife, then cut horizontally into two even layers. Wash and dry springform pan, return side of pan to latched position and line bottom with a fresh parchment paper. Transfer bottom cake layer, split side up, to prepared pan.

Step 5

Pour filling into pan, spreading to edges of cake in an even layer. Transfer top layer of cake to pan(top side up), loosely cover and refrigerate until cold, at least 2 hours and up to 1 day.

Step 6

Frosting:
Combine egg whites, sugar, and salt in the heatproof bowl of a mixer set over(but not in)a pan of simmering water. Heat, whisking, until mixture is hot to the touch and sugar has dissolved(it should feel smooth when rubbed between your fingers). Transfer to to mixer fitted with the whisk attachment. Beat on medium speed 5 minutes. Increase send to med-high and continue beating until stiff peaks form and mixture is glossy and cooled, 5-6 minutes more. Reduce speed t medium; beat n butter, 1 tablespoon at a time. Beat in bite chocolate until thick and smooth( if frosting seems too thin, it was too warm when butter and chocolate were added.) Refrigerate until cool and beat again before using.

Step 7

Unlatch and remove side of pan from chilled cake. Use a spatula to smooth away any filling protruding from middle along side of cake. Line the edges of a cake plate or stand with strips of parchment. Transfer cake to plate. Spoon frosting onto top of cake and sides with a spatula. Discard parchment strips and refrigerate cake til icing is set, at least 20 minutes, or lossless covered, up to three days.

Step 8

Slice and serve.