In a large bowl, whisk together the flour, sugar, baking powder and salt.
In a separate bowl, whisk together the buttermilk, eggs and butter. Add the liquid ingredients to the dry ingredients and whisk until just combined (the batter will be a bit lumpy). Using a spoon, fold in the macaroni and cheddar.
Preheat a griddle or large nonstick skillet over medium-low heat and lightly grease. Using a 1/4-cup measure and working in batches of 4, scoop the batter onto the griddle to make pancakes. Cook until the undersides are golden-brown and bubbles start to form on the top, about 5 minutes. Flip and cook until the second side is golden-brown, 3 to 4 minutes. repeat with the remaining pancake batter. Serve with maple syrup.