1. Preheat oven to 475°. Whisk together flour and sugar in a large bowl.
2. Stir together buttermilk and 1/2 cup melted butter in a small bowl. (Butter will clump.) Stir buttermilk mixture into flour mixture until dough pulls away from sides of bowl. Drop dough by level scoops, 1 inch apart, onto a parchment paper-lined jelly-roll pan. (Use a 2-inch cookie scoop.)
3. Bake at 475° for 12 minutes or until golden brown. Brush with 2 Tbsp. melted butter, and serve.