Preheat oven to 350ºF. Line a sheet pan with parchment paper.
Place flour, baking powder, salt, and sugar in a large mixing bowl. Cut butter into ½ tablespoon-sized-bits and add to the flour. Using your fingertips or a pastry cutter, work the butter into the flour mixture until it resembles coarse meal. Make a well in the center of the flour and pour in all the heavy cream and the half and half.
Stir the dry ingredients into the cream and mix with a wooden spoon until dough just begins to come together into a ball. Turn dough onto a lightly floured surface and knead 2 or 3 times to form a cohesive mass. Do not overwork the dough.
Using a rolling pin, roll the dough to a 1-inch thickness. The correct thickness is the key to obtaining a stately biscuit.
Dip a 2 ½ inch biscuit cutter in flour, then cut the dough. Repeat until all the dough has been cut. Scraps can be gathered together and re- rolled one more time.
Place the biscuits on the prepared sheet pan, leaving about ¼ inch between them.
Brush the tops of the biscuits with 1 tablespoon of half and half and sprinkle with 1 tablespoon of sugar.
Bake for 20 minutes. Biscuits will be lightly browned on top and flaky in the center when done.