Melt the butter in a 2 quart sauce pot over medium to high heat; add sausage and cook, while stirring constantly until the sausage browns (8-10 min).
Season with sage, sugar, salt and pepper. Stir in 3 Tbsp flour and continue cooking for 2 min.
Add the whole milk and bring to a boil while constantly stirring (3 cups of milk for a thicker gravy or 4 cups for a traditional gravy). Cool and reserve.
Preheat oven to 325 degrees. Lightly spray a 12-cup muffin tray with non-stick spray.
Roll out 12 biscuits to 1/4-inch thickness, reserving the other 6. Press 12 flat biscuits into the muffin cups, making sure the biscuit is flush against the tray with no air pockets.
Fill the biscuit pockets with about 3 tablespoons of gravy mixture.
Cut remaining 6 biscuit circles in half. Remold each half biscuit into a small circle (top of the biscuit); roll into 1/4-inch thickness, and place on the biscuit pocket. Crimp the sides to make sure the top and cup are sealed together.
Bake in preheated oven for 12-15 minutes, until golden brown.