Preheat the oven to 350 degrees. Line cupcake pans with paper liners.
In the bowl of an electric mixer fitted with the paddle attachment, cream the butter, the granulated sugar and the brown sugar on medium-high speed until light and fluffy.
With the mixer on low speed, add the eggs one at the time and mix until incorporated.
In a separate bowl, whisk together the buttermilk, vanilla, coffee, and sour cream.
In a separate bowl, sift together the flour, baking soda, salt and cocoa powder.
In three parts, alternately add the dry ingredients and the buttermilk to the butter mixture, beginning and ending with the dry ingredients. Mix on low speed until just combined. Add the crushed Oreos to the cupcake batter and mix with a spatula, until combined.
Divide the batter among the cupcake tins (one rounded standard ice cream scoop per cup is the right amount) and bake for 20 to 25 minutes, until a toothpick comes out clean. Cool for 10 minutes, remove from the pans, and allow to cool completely before frosting.