Preheat the oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
In a large bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt.
Add eggs, buttermilk, oil, and vanilla extract to the dry ingredients and mix until well combined.
Stir in the hot coffee until the batter is smooth and thin.
Divide the batter evenly between the prepared cake pans.
Bake in the preheated oven for 30-35 minutes or until a toothpick inserted into the center comes out clean.
Allow the cakes to cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely.
To make the frosting, beat the softened butter in a mixing bowl until creamy.
Gradually add powdered sugar, cocoa powder, heavy cream, and vanilla extract, beating until smooth and creamy.
Place one cake layer on a serving plate, spread a layer of frosting on top, then place the second cake layer on top.
Cover the entire cake with the remaining frosting and smooth the top and sides.
Sprinkle the crushed Oreo cookies on top of the cake and gently press them into the frosting.
Refrigerate the cake for at least 1 hour before serving to allow the frosting to set.
Slice and enjoy the delicious Oreo Drip Cake!