Zucchini Brownies

Preheat oven to 350 degrees F. In a small saucepan over low heat, melt butter and 1 cup chocolate chips. Remove saucepan from heat and stir in sugar, egg and egg yolk, and vanilla. Fold in grated zucchini. In a bowl, whisk together flour, baking powder, and salt. Add wet ingredients to dry and stir until totally combined. Pour mixture into a parchment-lined or greased 8-x-8" baking dish or pan. Bake until moist crumbs cling to toothpick, about 25 minutes. Let cool 1 hour. Make frosting: In a small saucepan over low heat, heat milk just until it bubbles. Add remaining 3/4 cup chocolate chips to a bowl and pour over milk. Let sit 5 minutes, then whisk until completely melted and no chocolate chunks remain. (Microwave on low for 30 seconds if chunks do remain.) Pour ganache over brownies and spread with a spatula to create an even layer. Refrigerate until firm, about 30 minutes. Slice into brownies and serve.