Process or whisk together the flour, sugar, baking powder, and salt.
Cut the cold butter cubes into the flour mixture by using a pastry cutter, a fork, or by pulsing a few times in a food processor, until mealy and butter is in pea-sized lumps. Transfer to a large bowl, if using the food processor.
In a small bowl, mix the buttermilk and vanilla extract.
Make a well in the center of the dry mixture and pour in the buttermilk and vanilla.
Gently fold until mixture is just combined. It will be shaggy and a bit crumbly. Turn out onto a lightly floured work surface and gently shape into a ball. Flatten until about1/2-inch thick, wrap in plastic wrap, and chill for 20 to 30 minutes.
Preheat oven to 425ºF.
Cut 2 1/2-inch to 3-inch rounds out of the dough. Place on a parchment-lined baking sheet, an inch or two apart. Brush with cream, sprinkle with sugar, and bake 15-18 minutes, or until biscuits are browned on top and cooked through. Let cool for about 15 minutes before putting together.