Preheat oven to 450°F (230°C).

In a skillet over medium-high heat, cook the breakfast sausage until browned and crumbled. Drain grease thoroughly and set aside.

Place the stick of butter into an 8x8 or 9x9 inch baking pan. Place the pan in the preheating oven until butter is fully melted (about 3-5 minutes). Remove carefully.

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

Pour in the cold buttermilk and stir until a wet, shaggy dough forms. Do not overmix.

Fold in the cooked sausage and shredded cheddar cheese until just combined.

Pour the batter over the melted butter in the baking pan. Use a spatula to spread it to the edges. Do not stir the butter into the dough; let it pool around the sides and top.

Use a knife to gently score/cut the raw dough into 9 squares.

Bake for 22–28 minutes until the top is golden brown and a toothpick comes out clean.

Allow to cool for 10 minutes so the biscuits absorb the remaining butter before serving.