• Preheat the oven to 180C/350F/Gas 4. Grease and line two 20cm/8in sandwich tins.
• Melt the chocolate in a bowl set over a pan of simmering water.
• Meanwhile, cream the sugar and butter together in a bowl until light and fluffy. Add the orange zest and juice and the melted chocolate. Slowly beat in the eggs, one at a time, until well combined.
• Sift the flour, baking powder and cocoa powder into the mixture and fold until well combined. Divide the cake batter between the two sandwich tins and bake for 25-30 minutes, or until cooked through.

Buttercream

• Beat the butter until pale and fluffy. Add the icing sugar a little at time until fully incorporated.
• Add in the orange food colouring and orange extract then mix until fully incorporated. Then fill a piping bag with a circle piping nozzle and pipe onto the first layer of cake.
• Once the bottom layer is fully covered with icing sugar, leave it for a minute to give the buttercream to harden a little bit. Then add the second layer on top of the buttercream gently, pipe more icing on to the top layer of the cake. Add a couple of slices of terry chocolate orange and enjoy.