Preparation:

Step 1: Bake the Chocolate Cake Layers

• Preheat your oven to 350°F (175°C). Grease and line three 9-inch round cake pans with parchment paper.
• In a large bowl, whisk together the flour, cocoa powder, sugar, baking powder, baking soda, and salt until fully combined.
• Add the milk, vegetable oil, eggs, and vanilla extract. Beat the mixture until smooth.
• Gradually add in the boiling water, mixing well. The batter will be thin, but this is normal.
• Divide the batter evenly between the three prepared cake pans.
• Bake for 25-30 minutes, or until a toothpick inserted into the center of the cakes comes out clean.
• Allow the cakes to cool completely in the pans before transferring them to a wire rack to cool completely.

Step 2: Prepare the Oreo Buttercream Frosting

• In a large bowl, beat the softened butter with an electric mixer until creamy and smooth.
• Gradually add in the powdered sugar, 1 cup at a time, mixing well after each addition.
• Add the heavy cream and vanilla extract. Continue to beat the mixture until fluffy and smooth. If the frosting is too thick, add a little more heavy cream to achieve a spreadable consistency.
• Gently fold in the crushed Oreos, mixing until well combined.

Step 3: Assemble the Cake

• Place the first chocolate cake layer on a serving plate or cake stand.
• Spread a generous layer of Oreo buttercream frosting on top of the cake layer, smoothing it out with an offset spatula.
• Repeat the process with the second and third cake layers, adding frosting between each layer and covering the entire cake with the remaining Oreo buttercream frosting.
• Use an offset spatula to smooth the frosting over the sides and top of the cake.

Step 4: Prepare the Chocolate Ganache Drip

• In a small saucepan, heat the heavy cream over medium heat until it begins to simmer.
• Place the semi-sweet chocolate chips in a heatproof bowl and pour the hot cream over the chocolate.
• Let the mixture sit for 2 minutes, then stir until smooth and glossy.
• Allow the ganache to cool slightly before drizzling it over the top of the cake. Let it drip down the sides of the cake for a dramatic effect.

Step 5: Garnish and Serve

• Decorate the top of the cake with extra crushed Oreos, mini Oreos, and chocolate sprinkles for a fun and festive look.
• For a cosmic touch, sprinkle edible glitter or colorful sprinkles on top of the cake to make it truly out of this world.
• Let the ganache set for a few minutes before slicing and serving.