Preheat oven to 180 C Lightly grease a 9×10 inch pan then set aside.
Take melted butter in a large bowl and stir in the sugar and vanilla.
Stir in the eggs one at a time, beating until mixed.
Add in the cocoa, flour, baking powder, salt and mix. Fold in the chocolate chips.
Pour mixture into the greased pan and bake at 180oC for 25-35 minutes or until toothpick comes out clean.
Remove from heat and allow brownies to cool before cutting into squares.
Melt the white chocolate.