Defrost the sausage before adding it to the skillet. In a small skillet, over medium-high heat, add sausages or ground sausage and cook for about 7-10 minutes, turning or stirring as needed, until cooked through. Remove from heat.
If using sausage links, remove sausage from the pan onto a cutting board, and chop into small pieces.
Preheat the oven to 425 degrees F.
In a medium-sized bowl, mix pancake batter, milk, oil until combined.
Spray mini or regular muffin pans with non-stick cooking spray.
Fill tins with pancake mix 1/2-3/4 full.
Add toppings to each muffin as desired. Add only a few crumbles or 2-3 small pieces of sausage to each muffin. Use the same rule of thumb for toppings such as berries or chocolate chips.
Bake in the oven for 10-12 minutes for mini muffins, and about 15-20 minutes for regular size muffins, or until a toothpick inserted through the center comes out clean and muffins are golden brown.