To make the cake, preheat oven to 350 degrees F. Butter and flour 2 8-inch or 9-inch cake pans (see Notes) and line bottoms with parchment paper. See my full tutorial on how to prep cake pans.

In a bowl, whisk together the coffee and cocoa powder until no lumps remain. Set aside. In another bowl, sift together the flour, salt, and baking soda.

In a large bowl, beat the sugar and eggs together until smooth and pale yellow in color. Stir in the sour cream, followed by the vegetable oil. Add the flour mixture all at once and stir until combined. Stir in the cocoa mixture and mix until smooth.

Divide the batter evenly between the prepared cake pans and bake until a toothpick inserted into the center comes out clean, about 25-35 minutes. Let cool in the pan for 10 minutes, then remove and place on a wire rack to cool completely.

For best results, completely chill cake layers before assembly.

If using instant pudding, follow instructions on box.

OR if making homemade pudding, in a medium saucepan over medium low heat, combine the milk, sugar, cocoa, cornstarch and sugar, and stir until smooth. Heat mixture until it just begins to steam.

In a medium bowl, whisk together the egg yolks. Slowly add the milk mixture to the egg yolks in a small stream while whisking constantly. When fully combined, pour back into the saucepan.

Place over medium heat and cook until thickened, about 4-5 minutes, while stirring constantly. Remove from heat and add vanilla extract. Chill in the fridge for at least 1 hour.

Use food processor to crush whole sandwich cookies into crumbs (do not remove filling). You can also place cookies in a ziplock bag and crush with a rolling pin.

With an electric mixer, beat whipping cream to stiff peaks.

Fold in 1/3 to 1/2 cup of the chocolate pudding, until desired color, flavor, and consistency is reached.

Place one cake layer on a cake stand or plate. Cover with approximately 1/2 cup chocolate pudding. Sprinkle with some oreo dirt.

Repeat with remaining layers.

Carefully frost cake with chocolate whipped cream.

Decorate cake tops and sides with remaining oreo dirt, or as desired.

Chill for at least 1 hour before serving. Cake can be assembled up to 24 hours in advance and stored in the fridge.