6 tbsp unsalted butter, softened
1 cup granulated sugar
1/2 tsp kosher salt
1 tbsp + additional tbsp vegetable oil
1 large egg
1 large egg yolk
2/3 cup buttermilk, room temperature
1 1/2 tbsp red food coloring
1 1/3 cups all purpose flour
1 tsp cocoa powder
1/2 tsp baking soda
2 8oz cream cheese
6 tbsp unsalted butter
1 cup confectioner’s sugar, sifted
blue food coloring
Adjust oven rack to middle and preheat to 350F. Line a muffin tin with cupcake liners. Stir butter, sugar and salt in a large bowl until creamy. Whisk in oil, then egg, yolk and buttermilk until combined.
Sift flour, cocoa and baking soda over wet ingredients and stir until just combined. Spoon into muffin tin and bake until centers are set, about 18-20 minutes. Cook for 5 minutes still in the pan and remove and cool on a wire rack until completely cool.
Beat cream cheese and butter until creamy. Add the sugar and combine until light and fluffy.
Spoon frosting into a bowl and add blue food coloring until color is adequate. Pack into a plastic bag and cut off the tip. Frost each cupcake and cool.