Heat oven to 350. Lightly grease a 9x13 baking dish. In a large saucepan, combine butter and white chocolate squares melt over medium heat stirring constantly. Remove from heat, cool only slightly. Stir in sugars and vanilla. Add eggs one at a time and beat after each addition. Add flour, baking powder and salt. stir until well blended and add coconut, nuts and chips. Stir well. Spread mixture evenly into prepared pan. Bake 30 minutes, text for doneness. I test at 25 for my oven. Cool completely before cutting. I don't ice these, the flavor is so distinct and hazelnuts are a standout flavor. I just use powdered sugar on each piece.