3 cups all-purpose flour
Pre-heat oven to 450F. In a large bowl, mix flour, baking powder, sugar, salt and cream of tartar. Working quickly, throw butter into flour mix and work it in with your hands until little balls form.
Make a well in the center of the flour/butter mixture and add butter milk all at once. With a large spoon stir mixture quickly, just until it's blended and begins to mass and form a sticky dough. (If dough appears super dry, add 1 to 2 tablespoons additional buttermilk.)
Immediately turn dough onto a generously floured surface. Using floured hands, knead briskly 8 to 10 times until cohesive ball of dough forms. Gently flatten dough with hands to even thickness. Using a floured rolling pin, lightly roll dough to a 3/4-inch thickness.
Note: I'm pathetic and totally botched the measuring process. I measured wrong and they came out a bit thin. Make sure to grab a ruler and measure them out to 3/4 of an inch. You want 'em pretty and tall.
You can use a 2 1/2 or 3 inch biscuit cutter. I just used a pint glass from The Onion. Whatever works for you. Cut the biscuits out and arrange on heavy baking sheet. Try to get as many as you can out of the first roll. Gather the excess dough and roll out again and cut more biscuits. I'd discard the excess dough after the second roll out because they'll turn out tough and chewy.
Place on upper third of oven and bake for 8 to 12 minutes until crusty and golden brown. Remove and enjoy with your favorite jam.