Line a baking sheet with parchment paper; set pan aside.

Using a large bowl, add flour, sugar, salt, baking powder and baking soda; stir until well combined.

Cut butter into ½” cubes and add to the bowl with the dry ingredients. Using a pastry cutter (or two table knives) cut in butter until it’s the size of small peas.

Add buttermilk; stir until well combined. (Note: The dough should be somewhat shaggy at this point.)

Turn dough out onto a lightly floured surface. Roll dough into an 8”x8” square. Cut dough into 4 equal pieces; stack each piece on top of themselves. Roll into a square again. Repeat process 2 more times.

Roll dough into an 8”x8” square (~1” thick). Using a 2½” round cookie cutter dipped in flour, press down without twisting cutter. Place biscuits 2” apart on prepared baking sheet. Reroll scraps as needed until all dough has been used.

Place pan in freezer for 15 minutes.

Preheat oven to 425°F.

Whisk egg with 1 Tbsp of water; brush egg wash on top of biscuits.

Bake for 15 minutes, or until tops are golden brown in color.

Let biscuits cool for 5 minutes before splitting.

Using a large skillet, add sausage and place over medium heat. Cook, stirring occasionally to break up the sausage, for 10 minutes, or until sausage is browned and fully cooked.

Add butter and continue cooking until melted.

Sprinkle flour on top. Continue cooking, stirring occasionally, for 3-4 minutes, or until the flour has been absorbed.

Add 2½ cups of milk and reduce heat to medium-low. Cook at a low simmer, stirring often, until gravy thickens and coats the back of a wooden spoon. (Note: If mixture is too thick, add up to ½ cup of additional milk until gravy reaches desired thickness.)

Serve over split or crumbled biscuits.