Marble Cupcakes

Directions

1. 1
   Preheat oven to 350F.
2. 2
   Line standard muffin tins with paper liners.
3. 3
   Sift together cake flour, baking powder, and salt.
4. 4
   Combine milk and cream.
5. 5
   With an electric mixer on medium-high speed, cream butter and granulated sugar until pale and fluffy.
6. 6
   Add eggs, one at a time, beating until each is incorporated, scraping down sides of bowl as needed.
7. 7
   Beat in vanilla.
8. 8
   Add flour mixture in three batches, alternating with two additions of milk mixture, and beating until combined.
9. 9
   To make chocolate batter, measure out 1 cup batter, and transfer to another bowl.
10. 10
    Combine cocoa and the boiling water in a bowl.
11. 11
    Stir into reserved 1 cup batter.
12. 12
    Fill prepared cups with alternating spoonfuls of vanilla and chocolate batter, filling each three-quarters full.
13. 13
    Run the tip of a paring knife or wooden skewer through batter in a figure-eight motion to make swirls.
14. 14
    Bake, rotating tins halfway through, until tops are golden and a cake tester inserted in centers comes out clean, about 20 minutes.
15. 15
    Transfer tins to wire racks to cool completely before removing cupcakes.
16. 16
    Cupcakes can be stored overnight at room temperature, or frozen up to 2 months, in airtight containers.
17. 17
    To finish, dust with confectioners sugar just before serving.