Preheat your oven to 375 and line two sheet pans with parchment

Cut your butter into small pieces. I usually try to cut each stick into about 24 pieces or so. The more you cut now the better. After the butter is cut put it back in the fridge or even the freezer for a couple minutes to make sure it is cold.

Add butter, baking powder, salt, sugar, baking powder, and flour to your food processor and pulse a few times until the butter is incorporated with the dry ingredients. It should resemble coarse meal.

Transfer to a large bowl and add the buttermilk. Mix gently with a fork or large spoon until the dough comes together. It will still be fairly craggy looking dough but that is what you want. Don't over mix. If you really want to save time you can do this step in a mixer but only mix for a few seconds.

Move the dough to a lightly floured surface (I usually use a Silpat for this) and gently bring the dough together and flatten until it is about 1 1/4 - 1 1/2 inches thick. If you want thicker biscuits go ahead and make the dough thicker

Cut out biscuits using a *round biscuit cutter. I usually use a 3 1/4 inch cutter but you can use bigger or smaller depending on what you want to use it for. Cut straight down and never, ever twist the cutter as you are cutting.

Reform the scraps and cut some more out. If you have enough scraps after the second cut you can do one more but the quality of the biscuits degrades with each cutting.

Place the biscuits on your parchment lined pans, brush with the beaten egg, and bake about 30 minutes until nice and golden brown.

Remove the biscuits from the oven and brush the tops with butter if you want. Optional but why wouldn't you want more butter???