Heat a large skillet over medium heat. Crumble sausage into pan and cook until well browned and no longer pink.
Now, add butter to the skillet and let it melt. Please note that if you have enough fat from the sausage then you may not need to add butter. Jimmy Dean sausage isn't super fatty so, I like to add some butter.
Sprinkle flour over the sausage/melted butter mixture. Stir it into the sausage mixture and cook to get rid of the raw flour taste, about 1-2 minutes.
Slowly add the milk to the sausage/flour mixture, stirring constantly until incorporated. Bring mixture to a low boil (bubbling slightly). You may need to turn the heat up to medium-high, just be careful not to burn it.
Once the gravy is gently boiling, turn the heat down to low and simmer the mixture until thickened. Add garlic powder, Worcestershire sauce, and salt and pepper, to taste.