01 -
Preheat the oven to 325°F and line a 12-cup muffin pan with paper liners.
02 -
Using an electric mixer, beat the softened butter and caster sugar together in a large mixing bowl until light and fluffy. Add the egg and continue beating until well incorporated.
03 -
In a separate bowl, sift together the all-purpose flour and cocoa powder.
04 -
In a jug, stir together the buttermilk, red food coloring, and vanilla extract.
05 -
Add half of the buttermilk mixture to the creamed butter mixture and beat to combine. Sift in half of the flour mixture, then add the remaining buttermilk mixture, followed by the rest of the flour. Beat until smooth and homogeneous.
06 -
Beat in the baking soda and white vinegar, ensuring the mixture is evenly combined.
07 -
Quickly divide the batter among the lined muffin cups. Transfer to the oven and bake for 20 to 25 minutes, until risen and a skewer inserted in the center comes out clean.
08 -
Remove cupcakes from the pan and transfer to a wire rack. Allow them to cool completely before icing.
09 -
Place the cream cheese in a large mixing bowl. Sift in the confectioners' sugar and add the vanilla extract. Stir until combined, then pour in the heavy cream and beat with an electric mixer until the icing is firm enough to pipe.
10 -
Transfer just under one third of the icing to a separate bowl and tint it with black gel food color. Color the remaining icing red with gel food color.
11 -
Fit a piping bag with a large closed star tip. Use a spatula to coat the inside of the bag with the black icing. Fill the center of the bag with the red icing, ensuring black covers the edges and red is in the middle. Twist the top to secure and eliminate air pockets. Squeeze out a bit to ensure both colors come through.
12 -
Pipe a swirl of two-tone icing onto each cupcake, starting at the center and spiraling outward in an anti-clockwise motion. Let the icing tail off at the edge and smooth with a finger or damp brush if needed. Repeat for all cupcakes.
13 -
Place the decorated cupcakes in the refrigerator until ready to serve.