In a mixing bowl combine flour, baking powder, and baking soda.
Using a box cheese grater placed over a piece of parchment paper, grate 6 of the 8 tablespoons of frozen butter, reserve the remaining 2 tablespoons for later (no need to keep it cold).
Add the grated butter to the flour mixture and gently combine using your hands. Place the bowl of flour mixture in the freezer.
Measure 1 cup of milk into a bowl and add the vinegar. Let it sit for 10 minutes.
After the 10 minutes, remove the bowl from the freezer, make a well in the butter and flour mixture and pour the milk mixture into the well. Gently stir the mixture with a wooden spoon about 15-18 times until the dough is fully combined, but still slightly sticky and lumpy.
Place dough on a lightly floured surface and sprinkle a little additional flour on top of the dough.
With floured hands, gently pat the dough into a rectangle about 5.5 inches by 11.5 inches and ½ inch thick.
Fold the dough over onto itself, then pat out that rectangle to its previous size. Repeat this process 4 more times (5 folds total). Cut biscuit shapes using a 2.25 inch diameter cutter, dipped in flour. Reshape leftover scraps to cut out more biscuits.
Place the biscuits almost touching on a jelly roll pan lined with parchment paper and bake at 475 degrees on the center rack of the oven for about 15 minutes, or until lightly browned on top. While biscuits are cooking, melt remaining butter in the microwave. When biscuits are done remove from the oven, brush with melted butter, and serve.