2 cups all-purpose flour ▢4 teaspoons baking powder ▢2 teaspoons sugar ▢½ teaspoon salt ▢½ teaspoon cream of tartar ▢½ cup unsalted butter chilled, plus melted butter for brushing ▢¾ cup buttermilk
Preheat the oven to 450°F. Sift flour, baking powder, sugar, salt, and cream of tartar together into a large bowl.
Cut in cold butter until the mixture is the consistency of coarse oatmeal. Make a well in the center of the mixture and pour in buttermilk. Stir with a wooden spoon until dough begins to come together.
Press dough together, but use your hands as little as possible, since it will warm up the butter in the dough.
On a lightly floured surface, roll out dough to about ¾ inch thick. Use a cookie cutter to cut 2-inch round biscuits, then place on an ungreased baking sheet.
Bake for 10 minutes, or until golden brown. Brush with melted butter as soon as biscuits come out of the oven. Serve warm.