Preheat the oven to 425°F (220°C).

Line a baking sheet with parchment paper.

In a large mixing bowl, whisk together the flour, baking powder, baking soda, and salt.

Add the cold, cubed butter to the dry mixture and mix until it resembles coarse crumbs.

In another bowl, mix together the sour cream and milk until smooth.

Pour the wet mixture into the dry ingredients and stir gently until just combined.

Turn the dough out onto a floured surface, gently knead it a few times, and roll it out to about 1 inch thick.

Cut into rounds using a biscuit cutter.

Place the cut biscuits on the prepared baking sheet.

Bake for 12-15 minutes until golden brown on top.