Ghostly chocolate traybake

Grease and line a 20x30cm cake tin (about 7.5cm deep) with baking parchment. Preheat the oven to 180ºC, gas mark 4. Tip the flour, cocoa, baking powder, bicarbonate of soda, salt and sugars into a large mixing bowl. Combine, breaking up lumps with the back of a spoon.

Melt 120g unsalted butter and 120g dark chocolate together in a large heatproof bowl over a pan of barely simmering water, making sure the bowl doesn’t touch the bottom; set aside to cool slightly. Bring a kettle of water to the boil. Put the espresso powder into a measuring jug and add 165ml just-boiled water; stir to dissolve.

In a bowl, use a balloon whisk to beat the eggs and yogurt together, then beat into the cooled chocolate mixture, followed by the coffee, until smooth and combined. Gradually whisk the wet mixture into the dry ingredients until thoroughly mixed. Spoon the cake mixture into the prepared tin. Bake for 25-30 minutes until risen and a skewer inserted in the centre comes out clean. Allow the cake to cool in the tin for about 20 minutes before lifting out, carefully peeling off the parchment and transferring to a wire rack to cool completely.

Meanwhile, make the icing. Tip 200g chopped dark chocolate into a heatproof bowl. Put the cream, golden syrup and 15g unsalted butter in a pan with a pinch of salt; set over a medium-high heat until it just comes to the boil. Pour the hot cream mixture over the chocolate; let it stand for a minute before whisking until glossy and smooth. Allow to cool and thicken before using – you can put it in the fridge to speed up the process

For the ghosts, line 2 baking trays with parchment. Put the white chocolate in a heatproof bowl and set over a pan of barely simmering water (don’t let it touch the base of the pan). Allow to melt, trying not to stir too much. With a dessert spoon, dollop the chocolate onto the parchment, then use a teaspoon to pull the dollop down to create a ghostly shape. On each shape, stick 2 chocolate balls or choco pops on for eyes and use the tube of icing to add a dot for the mouth. Transfer the trays to the fridge to set (about 30 minutes).

Put the cake on a large board and spread the top and sides with the thickened icing. Carefully arrange the ghosts over the top and serve.