01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper cupcake liners.
02 - Set one whole Oreo cookie into the bottom of each cupcake liner.
03 - In a medium bowl, whisk together the all-purpose flour, cocoa powder, baking soda, and salt until evenly distributed.
04 - In a large bowl, beat the softened butter and granulated sugar with an electric mixer until pale, light, and fluffy.
05 - Add the eggs one at a time, mixing thoroughly after each addition until fully incorporated.
06 - Blend in the buttermilk, vanilla extract, and red food coloring until the mixture is smooth and uniformly colored.
07 - Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until just combined. Do not overmix.
08 - Divide the batter evenly among the prepared liners, filling each about three-quarters full to cover the Oreo at the bottom.
09 - Bake for 18 to 20 minutes, or until a toothpick inserted into the cake portion comes out clean. Transfer to a wire rack and cool completely before frosting.
10 - Beat the softened cream cheese and butter together until smooth and creamy. Add the sifted powdered sugar and vanilla extract, then mix until light and fluffy. Gently fold in the crushed Oreo cookies.
11 - Pipe or spread the frosting generously over the cooled cupcakes. Garnish with additional Oreo crumbs or mini Oreo cookies if desired.