Brew the coffee and let cool to room temperature.

Preheat the oven to 350°F.

Line 15 muffin tins with cupcake paper and set aside. You’ll need to use two standard size muffin pans for this recipe.

In a large mixing bowl, whisk together cooled coffee, buttermilk, oil, egg and vanilla until thoroughly combined.

Sift flour, cocoa powder, baking soda, baking powder in another bowl, add salt and sugar and whisk until evenly distributed. Add the flour mixture into the wet ingredient mixture and stir until a smooth batter forms.

Add a whole Oreo to the bottom of each cup and add batter directly on top. Fill each cup only ⅔ to ¾ full.

Bake for 18 - 19 minutes until a toothpick inserted in the middle of the cupcakes comes out clean with just a few crumbs attached.

Allow the cupcakes to rest in the pan for 10 - 15 minutes, until cool to the touch, before removing them from the pan and setting them on a wire rack to cool completely.

Add butter, cream, and vanilla extract to the stand mixer bowl.

Sift powdered sugar into the bowl and add the salt.

Stir to incorporate all of the ingredients, then increase the mixer speed gradually to high and beat until the frosting is lighter in color and fluffy, about 5 - 15 minutes

Ground the Oreos finely in a food processor or blender, stir into the buttercream until evenly mixed.

Fill a pastry bag fitted with a piping tip of your choice, preferably one with a large opening, and pipe swirls on top of the cool cupcakes.