Chef John's Boston Cream Pie

Recipe View Preheat oven to 350 degrees F (175 degrees C). Grease and flour two 8-inch round cake pans. (5 minutes)

Recipe View In a large bowl, combine yellow cake mix, eggs, water, and vegetable oil. Beat with an electric mixer on medium speed for 2 minutes, scraping down the bowl as needed. (2 minutes)

Recipe View Divide the cake batter evenly between the two prepared cake pans. (2 minutes)

Recipe View Bake in the preheated oven for 33 to 38 minutes, or until a toothpick inserted into the center comes out clean. Let cakes cool in pans for 10 minutes before inverting onto a wire rack to cool completely. (50 minutes)

Recipe View In a heatproof bowl, whisk together eggs, cornstarch, and granulated sugar until pale and smooth. Set aside. (3 minutes)

Recipe View In a medium saucepan, combine 1 cup heavy cream, whole milk, and 1/2 tablespoon butter. Heat over medium heat until the mixture just comes to a simmer. (8 minutes)

Recipe View Gradually whisk the hot cream mixture into the egg mixture, tempering the eggs. (2 minutes)

Recipe View Return the mixture to the saucepan and cook over medium-low heat, whisking constantly, until the custard thickens enough to coat the back of a spoon, about 1 minute. (1 minute)

Recipe View Strain the custard through a fine-mesh sieve into a clean bowl to remove any lumps. Stir in vanilla extract and salt. Cover the surface of the custard with plastic wrap to prevent a skin from forming, and refrigerate for at least 3 to 4 hours, or until completely chilled. (4 hours)

Recipe View Place chopped dark chocolate in a heatproof bowl. In a small saucepan, heat 1/2 cup heavy cream and 1 teaspoon butter over medium heat until simmering. Pour the hot cream over the chocolate and let it sit for 1 minute to soften the chocolate. Whisk until smooth and glossy. Let cool slightly until thickened but still pourable. (20 minutes)

Recipe View Place one cake layer on a serving plate, flat side up. Spread the chilled pastry cream evenly over the cake layer, leaving a 1-inch border. Top with the second cake layer, rounded side up. Gently press down to adhere. (5 minutes)

Recipe View Pour the cooled chocolate ganache over the top cake layer, allowing it to drip down the sides. Refrigerate for at least 30 minutes to allow the ganache to set before serving. (30 minutes)