01 - Preheat the oven to 350°F and line a 12-cup muffin tin with cupcake liners.
02 - Place one whole Oreo cookie at the bottom of each cupcake liner.
03 - In a medium bowl, whisk together the 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 - Mix in the buttermilk, vanilla extract, and red food coloring until the mixture is smooth and evenly colored.
07 - Gradually add the dry ingredients to the wet mixture, mixing on low speed until just combined. Avoid overmixing.
08 - Divide the batter evenly over the Oreo cookies in the cupcake liners, filling each liner about three-quarters full.
09 - Bake for 18 to 20 minutes, or until a toothpick inserted into the cupcake portion comes out clean. Let the cupcakes cool completely in the pan 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 onto the cooled cupcakes. Garnish with extra Oreo crumbs or mini Oreo cookies if desired.