First up it’s time to make the sponge; Preheat the oven to 190°C/170°C Fan oven/Gas mark 5 and grease and line 2x7” round cake tins.
Pop you butter and sugar into a large bowl and cream together until light and fluffy. Mix in your eggs until your mixture is smooth. Sieve your flour and Baking Powder on top and pop in your ground almonds and lime zest, fold through the until it’s all nicely combined.
Divide equally between your prepared cake tins and bake for 25 minutes until risen and golden, to check your cakes are baked pop a skewer into the centre and it should come out clean.
Whilst your cakes are baking make the drizzle, pop all the ingredients into a saucepan and heat over a medium heat until the sugar has dissolved. Turn up the heat and allow to boil for 1 minute and then set aside. Once your cakes are baked, remove the mint leaves from the drizzle and skewer a few holes in the top of your cake. Pour the drizzle over the sponges and allow to soak in. Leave your cakes to cool in the tin for 15 minutes and then pop onto a wire rack to cool completely.
Once your cakes are cool it’s time to decorate! Let’s make the buttercream, pop the butter in a large bowl and beat until softened and paler in colour – this is easiest to do with an electric hand whisk or free standing mixer. Gradually add the icing sugar mixing well after each addition. Finally pour in the lime juice and rum and beat your buttercream until it has a light and fluffy texture.
Use a serrated knife to cut the domed top of one layer of sponge and pop onto your cake board or serving plate. Spread a layer of buttercream over the top of the sponge and sandwich the other sponge layer on top. Spread the remaining buttercream over the top and around the sides of the cake using a scraper or palette knife to smooth it out.
Arrange the lime wedges, mint leaves and blackberries around the edge of the cake. Ta-dah! Your zesty mojito cake is ready to serve!