1. Preheat the oven to 450 degrees F. Line a large baking sheet with parchment paper and set aside.
2. In a large bowl, whisk together flour, baking powder, sugar, baking soda, and salt. Mix in cold butter with your fingertips until mixture resembles coarse meal. Stir in Cheddar cheese and sage. Add buttermilk and stir with a spatula until just combined.
3. Drop round spoonfuls of dough, about three tablespoons, onto prepared baking sheet. Brush biscuits with melted butter. Bake for 12-15 minutes or until tops are golden brown. Remove from oven and serve warm.