In a large bowl, combine pancake mix, eggs and milk being careful not to over-mix.
Divide batter evenly onto two parchment paper-lined 17x11 inch baking sheets. Spread evenly and bake for 15 minutes.
In a large bowl, combine eggs, milk, salt and pepper. Pour the eggs onto a parchment paper-lined 17x11 inch baking sheet. Spread evenly and bake for 15-17 minutes.
Line another 18x13 inch baking sheet with parchment paper and spread out the sausage from corner to corner. Decrease oven temperature to 350˚F (180˚C) and bake for 20 minutes.
Drain fat, and sprinkle cheese on top of the sausage. Bake for another 5 minutes at the same temperature.
On a cutting board, layer the sandwich starting with a pancake, followed by sausage, egg, and the second pancake. Slice into breakfast size sandwiches and serve immediately, or wrap in parchment and freeze in a container for up to 1 month.