Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish.

Unroll the crescent roll dough and press it into the bottom of the greased baking dish, sealing any seams.

Cook the breakfast sausage in a skillet over medium heat until browned and fully cooked. Drain any excess grease.

Spread the cooked sausage evenly over the crescent roll layer.

In a mixing bowl, whisk together eggs, milk, salt, and pepper. Pour the mixture over the sausage.

Sprinkle shredded cheese evenly over the top. Add optional vegetables like diced bell peppers or spinach if desired.

Bake in the preheated oven for 25-30 minutes, or until the eggs are set and the top is golden brown.

Remove from the oven and let the casserole cool for 5 minutes before slicing and serving.