Preheat an oven to 350 degrees F (175 degrees C). Grease a 9x13 inch baking dish.
Place cottage cheese, eggs, flour, sour cream, salt, and pepper in a food processor. Process until smooth. Mix spinach, cottage cheese mixture, and 2 cups of Cheddar cheese in a bowl, then spread into the prepared baking dish.
Bake in the preheated oven until a knife inserted into the center comes out clean, about 45 minutes. Top with the remaining 2 cups of Cheddar cheese and continue baking until cheese has melted, about 10 minutes.
