Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13-inch baking pan.
Mix baking mix, 1 cup Cheddar cheese, milk, maple syrup, eggs, and sugar together in a bowl; pour into prepared pan.
Bake in the preheated oven until a toothpick inserted in the center comes out clean, 20 to 25 minutes. Sprinkle bacon and remaining 1 cup Cheddar cheese over casserole; return to oven until cheese is melted, about 5 more minutes.