In a medium bowl, whisk together the flour, sugar, baking powder, baking soda, and salt.
In a separate bowl, whisk the buttermilk, egg, and melted butter until combined.
Pour the wet ingredients into the dry ingredients and stir until just combined; do not overmix. Set the pancake batter aside.
Preheat a non-stick skillet or griddle over medium heat and lightly grease with cooking spray.
Pour about 1/4 cup of pancake batter onto the skillet to form small pancakes approximately 3 inches in diameter. Cook until bubbles form on the surface and edges look set, about 2 minutes. Flip and cook for another 1-2 minutes until golden brown. Repeat until you have 8 pancakes. Set aside to cool.
In the same skillet, cook the sausage patties over medium heat until browned and cooked through, about 4 minutes per side. Remove and set aside.
Spray the skillet lightly with cooking spray. Crack one egg into a small bowl and gently slide it into the skillet. Use a spatula to carefully break the yolk and spread the egg evenly into a round shape about 3 inches in diameter. Cook until the egg is set, about 2-3 minutes, then flip and cook for another 1 minute. Repeat for all 4 eggs.
To assemble each McGriddle, place one pancake on a clean surface, top with one sausage patty, one cooked egg, and one slice of American cheese. Top with another pancake to form a sandwich.
Wrap each assembled sandwich tightly in plastic wrap, then place all wrapped sandwiches in a freezer-safe zip-top bag. Freeze for up to 1 month.
To reheat, unwrap a sandwich and microwave on high for 1 to 2 minutes or until heated through. Alternatively, reheat in a toaster oven at 350°F (175°C) for 10-12 minutes.