Place the flour, baking powder, baking soda, sugar, and salt in a large bowl or food processor fitted with a metal blade to combine, or whisk in a large bowl.
Cut in the butter until it resembles coarse meal with a few slightly larger bumps. Make a well in the center of the flour mixture.
1 Cup Butter
Stir in 1 1/2 cups buttermilk with a rubber spatula or fork until just starts to come together then turn out onto a counter top. Knead 3-4 times, but it should still look lumpy.
1 1/2 Cups Buttermilk
Roll out about 1" thick. Place a 3 1/2" cutter in flour then cut straight up and down through the dough.
Arrange with sides of the biscuits touching on a parchment lined baking sheet and brush with the remaining 2 tablespoons buttermilk, bake 8-10 minutes.Remove from the oven and brush with melted butter.