Chocolate Baileys cake

Method

1. Heat the oven to 160°C fan/gas 4. For the cake, put the white chocolate, butter, milk and Baileys in a pan and warm over a medium heat, stirring until melted and smooth. Add the sugar, vanilla and a pinch of salt. Use a balloon whisk to combine, then pour into a large mixing bowl and set aside to cool.
2. Add the eggs to the cooled chocolate mixture, then whisk until combined. Sift in the flour, baking powder and nutmeg, then stir until just combined. Divide the batter evenly between the prepared cake tins, then bake for 30-40 minutes until well risen, golden and a skewer pushed into the middle comes out clean. Cool the cakes in the tins for 10 minutes, then turn out onto a cooling rack and cool completely.
3. Make the ganache. Put the chopped chocolate in a large bowl. Combine the cream and Baileys in a small pan and bring to a simmer over a medium heat. Pour the hot cream mix over the chocolate, leave for 5 minutes, then stir gently until smooth. Cover and set aside to cool.
4. When ready to assemble the cake, make the mascarpone buttercream. In a large bowl, beat the softened butter and icing sugar together until pale and fluffy. Add the mascarpone and vanilla, then mix on a low speed until just combined.
5. To assemble, slice the cakes horizontally with a bread knife so you have 4 equal rounds. Secure one round on a cake board or serving plate with a little buttercream. Top with a third of the ganache, then repeat with the remaining cake rounds and ganache. Spread the cake top and sides with a thin layer of plain buttercream. Use a cake scraper or spatula to smooth, then chill the cake for 20 minutes to firm up (this is the crumb coat).
6. Divide the remaining buttercream into 3-4 small bowls. Leave one portion plain, then add some of the espresso liquid to the other portions so you have varying shades of coffee colour from light to dark brown. Starting with the darkest portion of buttercream, cover the cake from the bottom up, finishing with the plain buttercream at the top. Smooth with a cake scraper to create an ombre effect where one colour blends into the next. If you like, decorate the sides with some gold leaf, and top with Lindor balls and edible gold balls.