01 -
Preheat the oven to 350°F. Line a cupcake pan with liners.
02 -
In a medium bowl, whisk together flour, baking powder, baking soda, and salt.
03 -
In a large bowl, cream the butter and sugar until pale and fluffy. Mix in yogurt or sour cream, then gradually add egg whites, beating well after each addition.
04 -
Alternate adding the dry ingredients with the milk and orange juice, beginning and ending with the flour mixture. Mix until just combined.
05 -
Fold in the vanilla or orange extract and finely grated orange zest.
06 -
Divide the batter evenly among the cupcake liners. Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Let cool completely before frosting.
07 -
To prepare the frosting, whip the butter until creamy. Gradually add the sifted powdered sugar, orange juice, extract, and food coloring. Mix until fluffy and well combined.
08 -
Once the cupcakes are completely cooled, frost them with the orange buttercream frosting and garnish with orange zest or small orange slices.