Bring a large pot of water to a boil. Cook the egg noodles according to package instructions.
Preheat your oven to 350 degrees. Spray a 3 quart baking dish with cooking spray. (A 9 by 13 inch baking dish will work great for this recipe.)
Over medium heat, and in a large saucepan, melt the butter. Sauté the garlic for about 30 seconds before adding the flour. Whisk in the flour until fully incorporated.
Very slowly, whisk in the milk. Add about 2 tablespoons (eye ball it, no need to measure) of milk at the time, only adding more milk once what you just added is fully incorporated. The more you add, the more quickly you can add more than 2 tablespoons at a time. This should take you less than 2 minutes to do.
Add in the chili powder, cumin, salt, black pepper, and cayenne to the sauce. Remove from the heat once fully combined.
Mix the cooked noodles, the sauce you just made, the salsa, black beans, frozen corn, shredded chicken, egg noodles, and 1 cup of cheddar cheese to the prepared baking dish.
Top with the remaining 1 cup cheddar cheese. Bake for 20 minutes and serve warm. See the post for details on storing left overs and reheating.