Preheat oven to 425°F. Line a baking sheet with a silicone baking mat or parchment paper.

In a medium sized bowl, combine flour, baking powder, and salt and whisk.

On a cutting board, cube the butter. Add the butter to dry mixture and cut in with a pastry blender or two butter knives.

Add in sour cream and milk and stir until a shaggy dough forms. At this point you'll need to use your hands to knead the dough until you reach a cohesive dough.

Roll the dough out onto a well-floured surface to a 3/4" thickness. Using a circle shaped cookie cutter, cut out the biscuits and place onto the prepared baking sheet. Bake for 10 to 12 minutes, or until golden brown. Brush with melted butter and serve immediately.