Seville orange & chocolate Bundt cake

Preheat the oven to 180ºC, gas mark 4. Melt 25g butter in a microwave or small pan and use it to grease a 22in Bundt tin, ideally with a pastry brush. Sprinkle in 2 tbsp flour and slowly rotate the tin, tapping as you go, until it fully coats the inside. Put the tin in the fridge while you make the batter – this helps with turning out the cake later.

Cut the rest of the butter into cubes and put 200g into a large bowl with the oil. Add the sugar and use an electric hand mixer to beat on a medium speed for about 4 minutes, until pale (or use a freestanding mixer). Crack in the eggs one at a time, fully incorporating each before adding the next. In a separate large bowl, use a balloon to whisk together the flour, ground almonds, baking powder and salt.

Bring a kettle of water to the boil. In a small bowl, mix the cocoa with 5 tbsp just-boiled water. Add ½ of the flour mixture to the butter mixture and fold in, then stir in 140ml of the orange juice. Repeat with the remaining flour and 140ml orange juice (reserving the rest for the icing). Fold in the orange zest. Pour ½ of the batter back into the flour bowl; stir in the cocoa paste to make a cocoa batter.

Spoon the batters alternately into the chilled Bundt tin, then ripple them together with the tip of a sharp knife (be careful not to scrape the tin). Bake for 45-50 minutes until a skewer comes out clean.

Leave the cake in the tin for 10 minutes, then turn it out onto a cooling rack with a tray underneath. Meanwhile, make the icing: in a large bowl mix the icing sugar with enough of the remaining orange juice to make a spoonable glaze (20-40ml). Beat in the remaining 25g butter. As soon as the cake is on the cooling rack, pour over the glaze, then allow to cool completely.