Preheat oven to 325°. Grease an 8x8” pan. Set aside.
Combine butter and chocolate in a heat-proof bowl set over a pan of boiling water. Stir until melted. Remove from heat and let cool. If the butter and chocolate separate while cooling, stir with a wisk. Sift together flour and baking powder in a medium bowl and set aside.
Beat eggs in an electric mixer until thick and creamy, about 5 minutes. Gradually beat in sugar and beat about 3 minutes more. Fold in the white chocolate mixture, alternating with dry ingredients.
Pour batter into pan and bake about 30-35 minutes. Cool completely.
While the brownies are cooling, toast the coconut in a 350° oven. Place coconut on a baking sheet in a single layer and place in oven. Watch it carefully, stirring often, so it doesn’t burn. It will start to turn golden in just a few minutes. Let cool.
Make the truffles by crumbling the brownies into a large bowl and mixing with the coconut. Form desired size truffles and chill until hard, at least 30 minutes (overnight works too). Melt your white candy melts according to package directions and dip the truffles, tapping the excess before placing on a wax-paper lined cookie sheet. Cover with sprinkles or more toasted coconut.