01 - Preheat the oven to 350°F. Line a standard 12-cup muffin tin with 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 together using an electric mixer until light and fluffy, approximately 3 minutes.
05 - Add the eggs one at a time, mixing well after each addition until fully incorporated.
06 - Blend in the buttermilk, vanilla extract, and red food coloring, mixing until the color is uniform throughout.
07 - Gradually add the dry ingredient mixture to the wet batter, folding gently until just combined. Avoid overmixing.
08 - Divide the batter evenly among the prepared liners, filling each approximately three-quarters full to cover the Oreo base.
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.
10 - Beat the softened cream cheese and butter together until smooth and creamy. Add the sifted powdered sugar and vanilla extract, then mix on medium speed until light and fluffy. Gently fold in the crushed Oreo cookies.
11 - Pipe or spread the frosting generously onto the fully cooled cupcakes. Garnish with additional Oreo crumbs or mini Oreo cookies if desired.