Preheat your oven to 175C and line an 8x8 inch tin with baking paper
Melt 2 cups of chocolate in a bowl over a saucepan with two inches of water on a low heat
Boil the butternut squash (peeled and chopped into chunks) for 10 minutes in a saucepan, then drain well and blend into a purée
Add 1 cup of the blended squash to the melted chocolate and mix well until fully combined
Pour the batter into the prepared baking pan, spreading it evenly
Bake for 25-30 minutes, or until a skewer inserted into the middle comes out clean
Allow the brownies to cool
Melt the extra 1 cup of chocolate in the same way as before and stir in the remaining 1 cup of squash purée
Spread the frosting onto the brownies, cut into squares and enjoy
