01 -
Preheat oven to 350°F. Line a muffin tin with cupcake liners.
02 -
In a bowl, mix flour, sugar, baking powder, baking soda, and salt.
03 -
Cream butter and sugar until light. Add eggs one at a time, then mix in orange juice and zest.
04 -
Alternate adding dry ingredients and buttermilk, mixing until just combined.
05 -
Divide batter into liners (¾ full). Bake 18-20 minutes. Cool completely.
06 -
Beat butter until smooth. Gradually add powdered sugar, cocoa, milk, and vanilla until fluffy. Pipe onto cooled cupcakes.