01 - Preheat the oven to 350°F. Line a standard 12-cup muffin tin with paper cupcake liners.
02 - Set one whole Oreo cookie into the bottom of each cupcake liner, pressing gently to seat it flat.
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 on medium speed until the mixture is pale, light, and fluffy.
05 - Add the eggs one at a time to the butter-sugar mixture, beating well after each addition until fully incorporated.
06 - Mix in the buttermilk, vanilla extract, and red food coloring, blending until the color is uniform throughout.
07 - Gradually add the dry ingredient mixture to the wet ingredients, folding gently with a spatula until just combined. Avoid overmixing.
08 - Divide the batter evenly among the prepared liners, filling each approximately three-quarters full to allow room for rising.
09 - Bake for 18 to 20 minutes, or until a toothpick inserted into the cake portion comes out clean. Transfer the tin to a wire rack and let the cupcakes cool completely.
10 - In a mixing bowl, 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 cream cheese frosting generously onto each cooled cupcake. Garnish with additional Oreo crumbs or mini Oreo cookies if desired.