These red velvet cupcakes are inspired by a recipe by Nigel Slater. A cream cheese-marshmallow frosting and a few sparklers add fun to the mix.
1large beetroot (about 300 gm)120 gmdark chocolate (66% cocoa solids)200 gmbutter, at room temperature190 gmcaster sugar4eggs, separated, at room temperature15 dropsred food colouring150 gm (1 cup)plain flour25 gm (¼ cup)Dutch-process cocoa2 tspbaking powderTo serve:silver cachousCream cheese-marshmallow frosting250 gmcream cheese, softened1 tbspliquid glucose or corn syrup150 gmcaster sugar1eggwhite2titanium-strength gelatine leaves, softened in cold water for 5 minutesScrapedseeds of 1 vanilla bean
Preheat oven to 160C. Cook beetroot in a saucepan of boiling water until tender (40 minutes to 1 hour), then set aside to cool. When cool enough to handle, peel, then transfer 200gm to a blender or food processor and blend to a smooth purée.
Melt chocolate in a bowl placed over a saucepan of simmering water, then set aside to cool slightly. Meanwhile, beat butter and sugar in an electric mixer until pale and creamy, then add yolks one at a time, beating well after each addition. Stir in melted chocolate, beetroot purée and food colouring, sieve flour, cocoa and baking powder over and fold to combine. Whisk eggwhites in a separate bowl to soft peaks, then fold into chocolate mixture. Spoon into a 12-cup muffin tray lined with paper cases and bake until an inserted skewer withdraws clean (20-25 minutes). Set aside to cool.
For cream cheese-marshmallow frosting, beat cream cheese in a bowl with a wooden spoon until very soft (2-3 minutes) and set aside. Stir glucose, 100gm sugar and 40ml water in a small saucepan over medium-high heat until sugar dissolves, then bring to the boil and cook until syrup reaches 118C on a sugar thermometer (4-5 minutes). Meanwhile, whisk eggwhite and a pinch of salt in an electric mixer until soft peaks form, gradually add remaining sugar and whisk until glossy. When syrup reaches 127C (3-4 minutes), remove from heat. Squeeze excess water from gelatine, add to syrup and stir to dissolve. Whisking on low-medium speed, gradually add syrup to meringue, then whisk on high speed until thick and cooled to room temperature (10-15 minutes). Beat in cream cheese and vanilla seeds and refrigerate, beating occasionally, until firm (15-20 minutes). Spoon into a piping bag fitted with a 1cm fluted tube, then pipe generous peaks on top of red velvet cupcakes. Scatter with silver cachous, stand to set (30 minutes), then serve.