Sift the flour, cocoa, baking powder and salt together. Set aside. Ina separate bowl cream the brown and white sugars, Stork, Nielsen-Massey Vanilla Extract and rum. Add the eggs one at a time, beating well after each addition. Add the dry ingredients in two additions, beating well after each half. Fold in the chocolate, fruit and nuts.
Grease a baking tin (9x13inches) with a little oil. It also helps to line the base with non-stick baking parchment. Spread the mixture evenly over the base. Bake for 25-30 minutes. The brownies should be crisp on top but should be a little gooey in the centre.
Remove from the oven and run a palette knife around the edges to loosen. Cut into 15 pieces and leave to cool for 20 minutes in the pan. Then remove carefully and store in an air-tight container.