Pigs in mud cake with chocolate, orange and stem ginger

You can pretty much make this cake in one bowl, so there is minimal washing up. That just leaves the orange buttercream and chocolate drip to make and the marzipan pigs to decorate.

Serves: about 20

Prep time: 10-15 mins (cake), 10 mins (buttercream), 10 mins (ganache drip), plus cooling time, assembly and decorating

Bake time: 40 mins

For the cake:
450g self-raising flour
650g caster sugar
140g cocoa powder
2 ½ tsp baking powder
320ml buttermilk (or whole milk combined with a teaspoon of lemon and left to thicken for 3 minutes)
140ml vegetable oil
3 large eggs
2 tsp vanilla bean paste
375ml boiling water

For the ganache drip:
100g dark chocolate, finely chopped
150ml double cream

For the buttercream:
400g unsalted butter, cubed, at room temperature
650g icing sugar
1 tbsp vanilla bean paste
Grated rind of 3 oranges
2-3 tbsp milk

Plus:
110g crystallised stem ginger
200g marzipan
Pink gel food dye
Black food dye
Vodka or gin

Preheat the oven to 170C/150C fan/325F/gas mark 3. Grease three 18cm cake tins and line the bases with greaseproof paper.

Stir together the flour, sugar, sieved cocoa powder and baking powder in a large bowl. Add the buttermilk, oil, eggs and vanilla and whisk until just combined. Add the boiling water and mix again until combined and glossy. Pour into the cake tins and then bake for about 40 minutes, or until a knife inserted comes out clean.

While the cakes are baking, make the buttercream. Add the butter, icing sugar and vanilla to a bowl and whisk until fluffy and almost white. Add the orange rind and whisk in. Add the milk gradually to loosen the consistency a little. Cover and set aside for now. Roughly chop the stem ginger ready for later.

When the cakes are ready, leave them to cool in the tins for five minutes, then run a knife around the edge and turn out on to a wire rack to fully cool.

Meanwhile, turn the marzipan pink by kneading in just a touch of gel food dye, then craft the marzipan pigs. Paint on eyes and nostrils using black food dye mixed with a little vodka or gin.

When cool, stack the cakes, separated by layers of buttercream with stem ginger. Then crumb-coat the sides with a thin layer of buttercream. Chill in the freezer until firm, then apply a second layer of buttercream, this time using a smoothing tool to create smooth sides and a clean edge. (Tip: heat a metal smoother a little to get a better finish.) Place the cake back in the freezer to chill again.

Make the ganache drip. Put the chopped chocolate in a heatproof bowl. Put the cream in a pan over medium heat. Take it off the heat as soon as it bubbles and pour over the chocolate. Leave to sit for two minutes, then stir until melted. If any solid chocolate remains, just return the mixture to the pan, stirring over a low heat.

When the ganache is of a nice dripping consistency (test it on the side of a glass), use a tablespoon to create carefully controlled drips down the side of your cake, then fill in the top with more chocolate, and arrange the pigs so that they are playing in the mud.

Baking with Kim-Joy: Cute and Creative Bakes to Make You Smile is published by Quadrille. To order for £15.84 (RRP £18) go to bookshop.guardian.com or call 0330 333 6846.