Few things go better than chocolate and orange, and this cake is made even more decadent with double buttercream.

Chocolate party cake

Ingredients:(Serves 20)

450g soft unsalted butter, plus extra for greasing650g icing sugar4 large free-range eggs250g self-raising flour2tsp baking powder75g cocoa powder1 x 300g tin of mandarin segments in juice150g light cream cheese

Method:

1. Preheat the oven to 180°C. Grease a 25-centimetre x 30-centimetre roasting tray and line with a sheet of damp greaseproof paper. In a food processor, blitz 250 grams each of butter and icing sugar, then crack in the eggs, add the flour, baking powder, 50 grams of cocoa, and a splash of juice from the mandarin tin, and blitz again until smooth. Use a spatula to gently spoon the mixture into the tray in an even layer, and bake for 20 minutes, or until risen and an inserted skewer comes out clean. Remove from the oven, leave for five minutes, and lift out on to a wire rack to cool completely.

2. Meanwhile, make the buttercream. In the processor, blitz the remaining 200 grams of butter and 400 grams of icing sugar until pale and fluffy, then pulse in the cream cheese, loosening with a splash of mandarin juice, if needed. Drain the mandarin segments and place on kitchen paper. On a serving board, carefully cut the cool cake through the middle to give you two large flat rectangles (I like to use a bread knife and run it under the hot tap first to help get a smooth cut). Spread a third of the buttercream over one of the cakes, dot over the mandarin segments, and sit the other cake on top. Trim the edges for a smart finish, if you like (you can call the offcuts chef’s treat!). Pulse the last 25 grams of cocoa into the remaining buttercream, and use it to decorate the top of the cake, making dips and peaks with the back of your spoon.

ENERGY 379kcalFAT 21.5gSAT FAT 13.1gPROTEIN 4gCARBS 45.3gSUGARS 35.1gSALT 0.4gFIBRE 0.9g

ONE: Simple One-Pan Wonders by Jamie Oliver is published by Penguin Random House © Jamie Oliver Enterprises Limited (2022 ONE), priced £28. Photography: © Richard Clatworthy, 2022. Available now.