In a large bowl, mix flour, baking cocoa, peanut butter, (all sifted), baking powder, baking soda, and salt. Set aside.
In a stand mixer with the whisk attachment, mix the room temperature butter on high speed until creamy (about 2 minutes). Add granulated sugar and continue mixing until creamy and fluffy (about 3-4 minutes). Add vanilla and peanut butter oil.
Reduce speed to the lowest setting. Spoon in dry mixture a little at a time. Alternate with milk until all of the dry mixture and milk is completely mixed in.
While the mixer is mixing on the lowest setting, slowly pour in the hot coffee until all mixed in. Do not overmix. You may have to stop the mixer an finish by hand so everything thoroughly incorporates.
Fill cupcake liners a little more than halfway. This batter should make 36 cupcakes.
Bake at 350°F for 15 minutes. or until the cupcakes pass the "toothpick" test.
Remove from oven and let cool completely on cooling rack before frosting.
For the buttercream
Mix together sifted powdered sugar and powdered peanut butter.
In a stand mixer, cream together butter and cream cheese until smooth.
A little at a time, add spoonfuls of the dry mixture to the stand mixer (on medium speed).
Add 2-3 of the tablespoons of milk one at a time in between portions of dry mixture. After all of the dry mixture is added, add another 1-2 tablespoons of milk if needed. At some point during the mixing process, add the vanilla.
After cupcakes are cooled completely, frost the cupcakes with your desired frosting method. Top with chocolate sprinkles or mini chocolate chips for some added texture and visual appeal. Enjoy!