1. Preheat Oven and Prepare Cake Pans: Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
2. Make the Cake Batter: In a large mixing bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt.
3. Bake the Cakes: Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
4. Prepare the Cream Filling: In a medium saucepan, heat the milk over medium heat until hot but not boiling.In a separate bowl, whisk together egg yolks, sugar, and cornstarch until well combined.
5. Assemble the Cake: Place one cake layer on a serving plate. Spread the cooled cream filling evenly over the top.Top with the second cake layer.
6. Serve and Enjoy: Slice the Boston Cream Pie Cake and serve it with your favorite beverage. Enjoy!