Preparation Steps

• Preheat the oven to 350°F. Grease and line two 8-inch round cake pans with parchment; lightly dust with flour or cocoa and tap out the excess.
• In a large bowl, sift together the flour, cocoa powder, baking powder, baking soda, salt, and instant espresso powder. Whisk briefly to blend and set aside.
• In a separate bowl, whisk the buttermilk, sour cream, oil, eggs, vinegar, vanilla, and red gel coloring until smooth and evenly colored.
• Make a well in the dry ingredients and pour in the wet mixture. Using a rubber spatula, fold the batter gently until just combined — avoid overmixing. The batter will be thick and slightly glossy.
• Fold in the coarsely chopped Oreos by hand so they stay chunky and distributed; reserve a few pieces for decorating. Divide the batter evenly between the prepared pans (use a kitchen scale or scoop for even layers).
• Bake on the center rack for 30–35 minutes, or until a toothpick comes out with just a few moist crumbs. Rotate the pans halfway through baking for even browning.
• Let the cakes cool in the pans for 15 minutes, then run a knife around the edges, invert onto a wire rack, peel off parchment, and cool completely before frosting (cooling fully helps the frosting hold).
• While the layers cool, make the frosting: beat the softened cream cheese and butter together on medium speed until very smooth and slightly aerated (about 2–3 minutes).
• With the mixer on low, add the powdered sugar one cup at a time until incorporated, then increase speed briefly to reach a spreadable consistency. Taste and adjust sweetness if needed.
• Fold in the finely crushed Oreos with a spatula so the frosting keeps a slightly speckled texture. Chill the frosting in the refrigerator for 20–30 minutes if it seems too soft to spread.
• Place one cake layer (flat side up) on a cake plate. Spread about a third of the frosting evenly over the top. Stack the second layer and press gently to level.
• Apply a thin crumb coat of frosting all over the cake to seal in crumbs. Refrigerate the cake for 30 minutes to firm the crumb coat.
• Finish with a generous second layer of frosting, smooth with an offset spatula, and decorate with reserved Oreo pieces or halves. Chill 20–30 minutes before slicing to make clean slices.