Preheat the oven to 180C /160C fan. Line the base and sides of a 20cm (8 inch) square tin with greaseproof paper. Make sure the paper sticks out 2.5cm (about an inch) above the rim of the tin.
Add the brownie mix to a bowl. Melt the butter (or dairy free alternative) and pour this over the brownie mix and stir until the mix starts to form a batter.
Lightly beat the eggs, and add to the batter with the coffee. Mix until well combined.
Spread the batter into the tin and smooth the top. Bake for 18-22 minutes until the top has formed a crisp layer. When they’re done, leave them to cool in the tin for 20 minutes before lifting out and transferring to a cooling rack. Use the paper to help you. Leave to cool completely before slicing.
