01 -
Turn your oven to 350°F (175°C) and get a muffin pan ready with cupcake liners.
02 -
Warm butter on low heat in a medium pot until melted. Remove from heat and mix in sugar until it’s smooth.
03 -
One at a time, beat the eggs in. Then mix in the vanilla extract.
04 -
In another bowl, toss together the flour, espresso powder, cocoa powder, and salt. Gradually fold this into the wet mixture until just blended.
05 -
Mix in milk until everything feels smooth and fully combined.
06 -
Spoon the batter into the cupcake liners, filling them about two-thirds full.
07 -
Pop the pan into the oven for 18-20 minutes. Check by sticking a toothpick in—a clean one means they’re done. Let the cupcakes cool down before you frost them.
08 -
Whip the softened butter in a bowl until it’s fluffy. Gradually add powdered sugar while beating, then mix in the espresso mixture and 1 tablespoon of milk. If it’s too thick, splash in another tablespoon of milk.
09 -
Spread the coffee buttercream over the cooled cupcakes and dig in.