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 ensure it sits 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 mixing bowl, beat the softened butter and granulated sugar together using an electric mixer on medium speed until the mixture becomes light and fluffy, approximately 3 minutes.
05 - Add the eggs one at a time to the butter mixture, beating well after each addition until fully incorporated before adding the next.
06 - Mix in the buttermilk, vanilla extract, and red food coloring, stirring until the color is uniform throughout the batter.
07 - Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until just combined. Avoid overmixing to keep the cupcakes tender.
08 - Divide the batter evenly among the prepared cupcake 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 cupcake portion (avoiding the Oreo base) comes out clean. Transfer to a wire rack and let cool completely before frosting.
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 with a spatula.
11 - Pipe or spread the frosting generously onto each cooled cupcake. Garnish with additional Oreo crumbs or mini Oreo cookies if desired. Serve immediately or refrigerate until ready to serve.