- 125 g (4.5 oz) dark chocolate, in drops or broken into pieces
- 50ml (2fl oz) milk
- 150 g (5oz) butter, softened, plus extra for greasing
- 150 g (5oz) caster sugar
- 3 eggs
- 200 g (7oz) plain flour, sifted
- 2 tsp baking powder
- 100 g (3.5 oz) after dinner mints (such as after eight mints), cut or broken into quarters
- chocolate mint leaves to decorate
For the icing
- 15 g (0.5 oz) mint leaves, finely chopped
- 250 g (9oz) icing sugar, sifted
- a few drops of green food colouring (optional)
- 100 g (3.5 oz) butter, softened
- 1 tblsp lemon juice
- a few drops of mint essence (optional)
- 20 cm (8in) square cake tin
- Preheat the oven to 180°C (350°F/Gas 4). If the tin has a removable base, butter the sides of the cake tin and line the base with a square of baking parchment, otherwise line the base and sides of the tin.
- Place the chocolate and milk in a heatproof bowl and set over a pan of simmering water. Leave just until melted, stirring occasionally, then remove from the heat and set aside.
- Cream the butter until soft in a large bowl or in an electric food mixer. Add the sugar and beat until the mixture is light and fluffy. Continuing to beat, pour in the melted chocolate, then add the eggs, one at time, beating continuously.
- Add the flour, baking powder and mints and gently fold in just until mixed. (You may find that some of the mints sink to the bottom of the cake during cooking, but this won’t matter.)
- Tip the mixture into the prepared tin and bake for 40–45 minutes or until a skewer inserted into the centre of the cake comes out with no batter sticking to it (although there may still be traces of mint or chocolate).
- Remove from the oven and allow to cool for 10 minutes in the tin before carefully removing the cake and leaving on a wire rack to cool down completely.
- Meanwhile, make the icing. Place the chopped mint in a food processor with 2 tablespoons of the icing sugar and the food colouring and whiz until combined. Alternatively, you could beat these ingredients together in a bowl with a wooden spoon.
- Add the butter, followed by the rest of the icing sugar and the lemon juice, and including some mint essence if you’d like to enhance the mint flavour, then whiz again until all the ingredients are combined and the mixture is smooth.
- Use a palette knife to spread the icing over the top of the cake, then decorate with the chocolate mint leaves.