Preheat your oven to 350°F (175°C).

In a skillet over medium heat, brown the breakfast sausage until fully cooked.

In a large mixing bowl, whisk together the pancake mix, milk, eggs, maple syrup, vanilla extract, baking powder, and salt.

Add the cooked sausage to the pancake batter and mix until well combined.

Grease your 9x13 inch baking dish and pour the batter mixture into it.

If using cheese, sprinkle it on top of the batter.

Bake in the preheated oven for 30 minutes, or until the top is golden brown and a toothpick inserted comes out clean.

Let the casserole cool for a few minutes before slicing.