1. Preheat your oven to 350°F. Line your muffin pans with cupcake liners and set aside. Boil 1/4 cup of water.
2. In a large bowl, add flour, cocoa powder, baking powder, baking soda, and salt. Sift to combine.
3. Add in the sugar and brown sugar stir until combined.
4. Add the oil, buttermilk, egg, cream beer, and vanilla extract. Stir until combined.
5. Add the instant coffee to the 1/4 cups boiling water and mix until dissolved.

6. Add the coffee to the mixing bowl and mix.

   
   

7. Pour the batter in the cupcake liners, filling each 3/4 of the way full.
8. Bake at 350°F for 17-20 minutes and then remove from oven and transfer to a wire rack to cool.

For Frosting

1. Finely crush Oreos.

2. In a stand mixer, add the butter on medium speed and beat for 1 minute. Add in the powdered sugar 1 cup at a time. Continue to mix to combine. 

3. Add the heavy whipping cream and vanilla extract. Mix on medium-high speed until the mixture is combined.
4. Add the Oreo crumbs on low-speed and combine.
5. Place one piping bag with a star tip into a large glass and fold the sides of the bag over. Scoop the Oreo frosting into the piping bag. Pipe the frosting on the cooled cupcakes. Top each frosted cupcake with a mini Oreo.