Preheat oven to 375° and spray a large baking dish with cooking spray.
In a large skillet cook sausage until browned all over.
If there is a lot of grease, drain if desired and sprinkle flour all over the sausage, cooking for just a minute longer.
Season with cayenne, salt and freshly cracked black pepper.
Pour milk over mixture, constantly stirring while bringing the mixture to a boil.
Reduce heat and simmer about 5 minutes until thick.
Remove from heat.
Place half your diced biscuits onto the bottom of your baking dish, bake those for a few minutes in the oven, remove from oven and pour gravy mixture on top.
Top with the remaining biscuits and brush with butter.
Place in the oven to bake 17-18 minutes, until biscuits are golden and sausage mixture is bubbling making sure that biscuits in the bottom of the casserole dish are baked through as well.