1. Preheat the oven to 180°C and grease a square tin.
2. In a bowl, mix the melted butter and sugar until creamy.
3. Beat in the eggs one at a time, then add the vanilla extract.
4. In a separate bowl, mix the cocoa powder, flour, salt and baking powder.
5. Stir the dry ingredients into the wet mixture until you have a smooth batter.
6. Pour the batter into the tin and bake for 20-25 minutes.
7. Leave to cool before cutting into squares.
**Nutritional Information:**
– Calories: 180 per serving
– Carbohydrates: 25 g
– Protein: 3 g
– Fat: 8 g
