Ingredients:

for the cupcakes
250 grams plain flour
2 tablespoons cocoa powder (sifted)
2 teaspoons baking powder
½ teaspoon bicarbonate of soda
100 grams soft unsalted butter
200 grams caster sugar
1 heaped tablespoon christmas-red paste food colouring
2 teaspoons vanilla extract
2 large eggs
175 ml buttermilk
1 teaspoon cider vinegar

for the buttery cream-cheese frosting
500 grams icing sugar
125 grams cream cheese
125 grams soft unsalted butter
1 teaspoon cider vinegar (or lemon juice)
chocolate sprinkles for decoration
red sugar for decoration

Method

For the cupcakes:

1. Preheat the oven to 170°C/gas mark 3/325°F, and line 2 muffin tins with paper cases.
2. Combine the flour, cocoa, baking powder and bicarbonate of soda in a bowl.
3. In another bowl, cream the butter and sugar, beating well, and when you have a soft, pale mixture beat in the food colouring – yes all of it – and the vanilla.
4. Into this vividly coloured mixture, still beating, add 1 spoonful of the dried ingredients, then 1 egg, followed by some more dried ingredients, then the other egg, followed by the rest of the dried ingredients.
5. Finally beat in the buttermilk and the vinegar and divide this extraordinary batter between the 24 cases.  Bake in the oven for about 20 minutes by which time the redcurrant-sorbet-coloured batter will have morphed into a more sombre, but still juicily tinted, sponge – more maroon acrylic than red velvet, to be honest.
6. Leave them to cool on a wire rack and do not ice with the frosting till absolutely cold.

For the buttery cream-cheese frosting:

1. Put the icing sugar into a processor and whizz to remove lumps.
2. Add the cream cheese and butter and process to mix.  Pour in the cider vinegar (or lemon juice) and process again to make a smooth icing.
3. Ice each cupcake, using a teaspoon or small spatula.
4. Decorate with chocolate sprinkles and red sugar, or as desired.

Make ahead note:

The cupcakes can be baked 2 days ahead and stored, un-iced, layered with baking parchment in airtight containers.  The frosting can be made 1 day ahead:  cover with clingfilm and refrigerate; remove from fridge 1-2 hours before needed to allow to come to room temperature then beat briefly before using.  Best iced and eaten on same day but iced cupcakes can be kept in fridge in airtight container for up to 1 day.  Bring to room temperature before serving.

Freeze note:

Un-iced cupcakes can be frozen, layered with baking parchment, in airtight containers for up to 2 months.  Defrost for 3-4 hours on a wire rack at room temperature.  Frosting can be frozen separately in airtight container for up to 3 months; defrost overnight in fridge then bring to room temperature and beat briefly before use.