Preheat oven to 375 degrees and line a baking sheet with parchment paper.

In a large bowl, combine flour, baking powder, salt, and sugar.

Cut butter into 1/2 tablespoon-sized pieces and add to flour. Use your fingers or a pastry cutter to work the butter into the flour mixture until it resembles coarse meal.

Make a well in the center and pour in heavy cream and half and half. Using a wooden spoon, stir the dry ingredients into the cream and mix just until it starts to form a dough.

Turn dough out onto a lightly floured surface and knead 2 to 3 times. Use a rolling pin to roll dough to 1-inch thickness.

Dip a 2 1/2-ich biscuit cutter (I think the one I used was slightly larger) in some flour and then cut the dough. Scraps can be gathered and rerolled 1 time.

Place biscuits on prepared sheet spacing apart by 1/4-inch. Brush tops with the 1 tablespoon half and half and sprinkle with sugar. Bake for 20 minutes.