Making Oreo Cake w/ Coffee Oreo Buttercream involves several steps, but don't worry — following this list will guide you through the process smoothly:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and flour three 8-inch round cake pans.

1. Combine Dry Ingredients: In a large mixing bowl, whisk together the flour, granulated sugar, cocoa powder, baking powder, baking soda, and salt.

1. Mix Wet Ingredients: In another bowl, combine the milk, vegetable oil, eggs, and vanilla extract.

1. Combine Mixtures: Gradually add the mixed wet ingredients to the dry ingredients and beat on medium speed until fully combined.

1. Add Boiling Water: Stir in the boiling water until the batter becomes smooth. This step will keep your cake moist.

1. Divide the Batter: Evenly divide the batter among the three prepared cake pans.

1. Bake: Place in the oven and bake for 30-35 minutes. Check with a toothpick; it should come out clean when done.

1. Cool the Cakes: Remove the pans from the oven and let them cool in the pans for about 10 minutes. Then, transfer the cakes to wire racks to cool completely.

1. Prepare the Buttercream: In a large bowl, beat the softened butter until creamy. Gradually add powdered sugar and cocoa powder, mixing continuously.

1. Dissolve Coffee: In a separate small bowl, dissolve instant coffee granules in 2 tablespoons of heavy cream. Add this mixture to the buttercream and beat until fluffy, adding more cream as needed for desired consistency.

1. Assemble the Cake: Once the cakes are completely cool, place one layer on your serving platter. Spread a generous layer of the Coffee Oreo Buttercream over the top.

1. Repeat Layers: Place the second layer and repeat the frosting step. Top it with the third layer, applying buttercream on top and around the sides of the cake.

1. Decorate: Finish decorating the cake with crushed Oreos on the top and sides for an extra touch.