1. Preheat your oven to 180°C (160°C fan) and grease a mini loaf tin with oil or margarine. Either line each mini loaf section with parchment paper, or use a strip to make removal easier once baked.
2. In a large bowl or stand mixer, cream together the softened butter, caster sugar, and light brown sugar until smooth and fluffy.
3. Add the eggs, one at a time, mixing well after each addition. Don’t worry if the mixture splits at this stage, it will come back together once the flour is added.
4. Stir in the Baileys and lemon juice mixture.
5. Melt the dark chocolate in the microwave, being careful not to overheat it. Once melted, add the chocolate to the batter and mix thoroughly.
6. Sift in the self-raising flour and cocoa powder, then gently fold them into the mixture until fully combined.
7. Spoon the cake batter into the lined mini loaf tins, filling each section about two-thirds full. Use a spoon or spatula to spread the mixture evenly into the corners.
8. Bake for 20 minutes, or until the cakes are springy to the touch and a skewer inserted into the centre comes out clean.
9. While the cakes bake, make the Baileys buttercream. Place the softened butter in your mixer and beat until lightened in colour. Gradually add the icing sugar, one tablespoon at a time, mixing well between each addition.
10. If the buttercream becomes too thick, add a small amount of Baileys to loosen it. Be careful not to add too much at once, as this can cause the mixture to split. The buttercream should be soft but firm enough to hold its shape when piped.
11. Once the mini loaves are baked, allow them to cool in the tin for a few minutes before transferring to a wire rack to cool completely.
12. Once the cakes are fully cooled, transfer the Baileys buttercream into a piping bag fitted with a 5-point star nozzle. Pipe the buttercream onto the cooled mini loaves and finish with festive sprinkles.
