Saute onions in butter with a pinch of salt in a deep frying pan.
Once onions are softened and slightly transparent brown ground beef in with the onions.
Once beef is cooked add in zucchini, yellow squash, paprika, black pepper, chili powder, and garlic powder. Stir in egg noodles. Cover with water then cover the pan and let cook 4 minutes.
Warm milk in microwave 30-45 seconds.
In a small mixing bowl add flour. Once the noodles have cooked 4 minutes remove lid and stir. Carefully remove some of the extra liquid from the noodles and whisk it in with the flour until a smooth paste is formed.
Carefully stir in the flour paste (this will thicken up to make the sauce). Stir in milk. Once warm slowly stir in cheese and spinach.
It is ready to serve when noodles are soft, cheese is melted, the sauce is thick, and spinach is slightly wilted.