Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
2. Make the Chocolate Cake Batter
In a large mixing bowl, combine the flour, sugar, cocoa powder, baking powder, baking soda, and salt.
Add the eggs, milk, vegetable oil, and vanilla extract to the dry ingredients. Beat on medium speed for about 2 minutes until well combined.
Carefully stir in the boiling water. The batter will be thin; this is normal.
Divide the batter evenly between the prepared cake pans.
3. Bake the Cakes
Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
Remove from the oven and allow the cakes to cool in the pans for 10 minutes before transferring to a cooling rack to cool completely.
4. Prepare the Cream Filling
In a mixing bowl, whip the heavy cream until it starts to thicken.
Gradually add the powdered sugar and vanilla extract, continuing to whip until soft peaks form. Set aside in the refrigerator until ready to use.
5. Make the Chocolate Glaze
In a small saucepan, heat the heavy cream over medium heat until it just begins to simmer.
Remove from heat and add the chocolate chips. Let it sit for a minute, then stir until smooth and glossy. Allow to cool slightly before using.
6. Assemble the Cake
Once the cakes are completely cool, place one layer on a serving plate.
Using a piping bag or a zip bag with a corner cut off, pipe a ring of the whipped cream filling around the edge of the cake layer. This will create a barrier to hold the filling inside.
Fill the center with the remaining whipped cream, then place the second cake layer on top.
7. Frost with Chocolate Glaze
Pour the chocolate glaze over the top of the cake, allowing it to drip down the sides. Use a spatula to smooth it out if needed.
Allow the glaze to set for a few minutes before slicing.
Notes and Tips
Storage: Store leftover cake in an airtight container in the refrigerator for up to 4 days. This cake is best enjoyed fresh, but the flavors only improve after a day in the fridge.
Cake Variations: You can add a layer of fruit, like sliced strawberries or raspberries, between the cake layers for a fruity twist.
Make Ahead: Both the cake and filling can be made ahead of time. Just assemble the cake on the day you plan to serve it for the freshest taste.