Combine flour, baking powder, baking soda and salt. Cube COLD butter and cut into flour mixture.
Add buttermilk and sour cream to flour mixture. Stir with a large fork just until combined (add a touch more milk if too dry)
Flour the work surface and knead the dough not more than 10-12 times. Roll out dough 1/2" thick. Cut with 2 3/4" biscuit cutter. (At this point you could layer these single layer in a freezer safe parchment lined container to freeze for later use)
Place in biscuit pan with sides slightly touching.
Bake at 450 for 8-12 min. (If baking from frozen state, reduce oven temp to 425 and bake 12-13 min)