Step 1: Bake the cake according to package directions for your chosen chocolate cake mix. I prefer using two 6x3 inch pans, but you can also opt for two 9 or 8 inch pans. As the cakes bake, enjoy the delicious aroma that fills your kitchen.
Step 2: Once baked, allow the cakes to cool completely. This is crucial for ensuring the layers don’t crumble when you assemble the cake.
Step 3: In a separate bowl, beat the heavy whipping cream using a whisk attachment until soft peaks form. Chill this whipped cream until you're ready to use it, as it will be folded into the cookie dough filling.
Step 4: Next, melt the butter in a microwave-safe bowl. Once melted, transfer it to an electric mixer fitted with a paddle attachment. While still warm, add both sugars and mix on low until combined. This step helps to dissolve the sugars, creating a smooth filling.
Step 5: Allow the butter-sugar mixture to cool for a few minutes, then turn the mixer on low again. Gradually mix in the vanilla extract and flour. Stir in the milk, one tablespoon at a time, until you achieve a smooth consistency.
Step 6: Now, gently stir in about 1 cup of the chilled whipped cream into your cookie dough mixture using the paddle attachment. This will lighten the filling, making it more indulgent. Feel free to add more whipped cream if you desire a fluffier texture.
Step 7: Next, fold in the chocolate chips, ensuring they are evenly distributed throughout the mixture. This will give each bite a burst of chocolate goodness.
Step 8: For the chocolate glaze, combine the semi-sweet baking chocolate, heavy cream, butter, and corn syrup in a bowl. Set the bowl over a pan of simmering water, ensuring the bottom of the bowl doesn’t touch the water. Stir until everything has melted together and is smooth.
Step 9: Once melted, remove from heat and stir in the vanilla extract. Allow the glaze to cool to room temperature before using.
Step 10: To assemble, slice your cake layers in half if desired. You can make a four-layer cake or keep it simple with two layers. Spread a generous amount of cookie dough filling between the layers, adding more as needed for a rich cookie dough experience.
Step 11: Top the entire cake with your chocolate glaze, or frost it with your favorite chocolate frosting. Remember, this cake is rich, so a little frosting goes a long way!