Buttermilk Drop Biscuits

Preheat oven to 475 degrees F. In a large bowl whisk together flour, baking powder, baking soda, sugar and salt. In a medium bowl, combine buttermilk and 1/2 cup unsalted melted butter, stirring with a rubber spatula until the butter forms small clumps. Mixture will still be somewhat watery but the butter should have formed quite a few lumps. Add buttermilk to the dry ingredients and stir with a spatula until just combined and the dough pulls away from the sides of the bowl. Drop by large spoonfuls onto a baking sheet lined with parchment paper. Place on the middle rack and bake for 12-14 minutes until tops are golden brown. Brush with remaining melted butter and let sit for a few minutes before serving.