These delicious brownies are still a once-in-a-while treat, it's true, but they are made at least a little more virtuous by the presence of a bag of kale in them! Let the kids help make them so they know it's in there but can be pleasantly surprised by the kale-less tasting result.
Preheat the oven to 180°C, gas mark 4. Grease and base line a 22cm square tin.
Melt the chocolate and butter in a bowl over a pan of simmering water.
Meanwhile, cook the kale in boiling water for 3-4 minutes, cool under cold water and drain well, squeezing out any excess liquid, then chop.
Whisk the sugar and eggs together until pale, stir in the chocolate mixture and kale.
Mix together the flour and baking powder and fold into the brownie mixture and pour into the prepared tin.
Bake for 35-40 minutes. Cool slightly before removing from the tin and cut into 12 pieces.