Preheat to 425°F and line a baking sheet with parchment paper.
In a large bowl, whisk together flour, sugar, baking powder, baking soda, salt, and pepper.
Add chilled butter cubes and cut them into the flour with a pastry cutter or your fingers until crumbly with pea-sized bits.
Pour in 1¼ cups of buttermilk and stir until a shaggy dough forms. Add more buttermilk, 1 tablespoon at a time, if it’s too dry.
Turn the dough onto a lightly floured surface and gently press it into a rough mound. If the dough looks dry or there are loose crumbs, just gather them up and either press them into the sides or pile them on top.
Then shape the dough into a rough rectangle and fold it into thirds, like you’re folding a letter. This helps create layers and also pulls in any dry bits. Just press or sprinkle loose crumbs on top before folding. Give the dough a quarter turn, pat it into a rectangle again, and fold it a second time. Each fold builds structure and flakiness, even if the dough feels a little messy at first.
Pat the dough into a final rectangle about 9×5 inches and 1 inch thick. Slice the rectangle in half lengthwise to create two long strips, then cut each strip into 5 equal pieces to make 10 square biscuits.
Place the biscuits on the prepared baking sheet and brush the tops with cream. If your kitchen is warm, chilling the biscuits for 10–15 minutes before baking helps keep the butter cold, which leads to better lift. Bake for 18–24 minutes, or until golden brown.
Make the Sausage Gravy:
In a large skillet over medium heat, cook the sausage until it’s fully browned, breaking it into small crumbles as it cooks. Don’t drain the fat, it's the base for the gravy. If the sausage is very lean, add a pat or two of butter to make up the difference.
Sprinkle flour over the sausage and stir well. Cook for 1 minute to eliminate raw flour taste.
Slowly pour in the milk while stirring to prevent lumps. Scrape up any browned bits from the bottom of the pan, they add great flavor. Keep stirring until the mixture is smooth, then let it simmer for 5 to 8 minutes, stirring often, until the gravy thickens.
Stir in the black pepper, then taste the gravy before adding any salt. Some sausage is salty enough on its own.
Split warm biscuits in half and ladle the gravy on top. Serve hot.
Notes
Chill the biscuits before baking: If your kitchen is warm, chill the shaped biscuits for 10–15 minutes.Grate the butter (or don’t): You can grate and briefly freeze the butter for quicker mixing, but I prefer cutting it into small chunks by hand. It creates larger chunks that hold steam pockets as they melt, which gives the biscuits extra flakiness.Freeze unbaked biscuits: Cut the dough, freeze the biscuits on a tray, and bake them straight from frozen. Just add 2–3 extra minutes to the bake time.Use whole milk in the gravy: It gives the creamiest texture, but other milk will work in a pinch.Reheat gravy with a splash of milk: It thickens as it cools, so stir in a bit of milk to bring it back to a pourable consistency.