1Preheat oven to 350'F
prepare two cupcake/muffin pans by lining with cupcake papers.
2Place a medium sized sauce pan over medium heat on the stove. Add black coffee, & butter to the sauce pan and bring it all to a low simmer.
Add cocoa powder and whisk until smooth. Take off the heat and set aside.
3Sift flour, baking powder, and salt together in a large mixing bowl. Set aside.
4In a large bowl with an electric mixer cream sugar and eggs together.
5Add vanilla extract and sour cream to the egg mixture and mix on medium speed until a bit fluffy. About 3 minutes.
6Add cocoa mixture to the egg mixture slowly. Be sure the mixture has cooled enough to where it will not cook the eggs.
Side note: if you are worried it might be a little too warm to add to the eggs, use a whisk to add about a tablespoon of the chocolate mixture to the egg batter and whisk vigorously. This will help temper the eggs to keep them from cooking.
7Add flour mixture to egg mixture in 3rds. Completely incorporate each 3rd of flour before adding next 3rd of flour.
8Pour batter out into cupcake pans.
Poke an unwrapped peanut butter cup down into the batter in each cupcake liner.
Bake on a center rack for 20-25 minutes, or until tooth pick comes out MOSTLY clean.
Cool completely on a wire wrack.
In a large mixing bowl cream butter and peanut butter together. Beat in vanilla. Then gradually beat in confectioner's sugar until complete incorporated and fluffy. Then slowly fold in the chocolate syrup until completely incorporated.
Once cakes are cooled, frost as desired. Garnish with peanut butter cups and chocolate syrup.