Recipe from The Hummingbird Bakery Cookbook.
For the cupcakes
60g unsalted butter, at room temperature
150g caster sugar
10g cocoa powder
20ml red food colouring (preferable Dr. Oetker Red Food Colouring)
1/2 teaspoon vanilla extract
150g plain flour
1/2 teaspoon salt
1/2 teaspoon bicarbonate of soda
1 and 1/2 teaspoons white wine vinegar
Preheat the oven to 170°C (325°F) Gas 3.
Put the butter and the sugar in a freestanding electric mixer with a paddle attachment (or use a handheld electric whisk) and beat on medium speed until light and fluffy and well mixed. Turn the mixer up to a high speed, slowly add the egg and beat until everything is well incorporated.
In a separate bowl, mix together the cocoa powder, red food colouring and vanilla extract to make a thick dark paste. Add to the butter mixture and mix thoroughly until evenly combined and coloured (scrape any unmixed ingredients from the side of the bowl with a rubber spatula).
Turn the mixer down to slow speed and slowly pour in half the buttermilk. Beat until well mixed, then add half the flour, and beat until beat until everything is well incorporated. Repeat this process until all the buttermilk and flour have been added. Scrape down the side of the bowl again. Turn the mixer up to a high speed and beat until you have a smooth, even mixture. Turn the mixer down to low speed and add the salt, bicarbonate of soda and vinegar. Beat until well mixed, then turn up the speed again and beat for a couple more minutes.
Spoon the mixture into the paper cases until two-thirds full and bake in the preheated oven for 20-25 minutes, or until the sponge bounces back when touched. A skewer inserted in the centre should come out clean. Leave the cupcakes to cool slightly in the tray before turning out onto a wire cooling rack to cool completely.
For the cream cheese frosting
300g icing sugar
50g unsalted butter, at room temperature
125g cream cheese, cold
Beat the icing sugar and butter together in a freestanding mixer with a paddle attachment (or use a handheld electric whisk) on a medium-slow speed until the mixture comes together and is well mixed. Add the cream cheese in one go and beat until it is completely incorporated. Turn the mixer up to medium-high speed. Continue beating until the frosting is light and fluffy, at least 5 minutes. Do not overbeat, as it can quickly become runny.
When the cupcakes are cold, pipe or spoon your frosting on top. You can pipe roses like these on using a Wilton 2D tip.