Cook noodles according to package directions in well-salted water, undercooking by 1 minute. Drain and rinse under cold water to stop the cooking process.
Meanwhile, make your sauce. In a large skillet over medium heat, melt your butter.
Add garlic, Italian seasoning, salt, onion powder and pepper and cook 1 minute.
Stir in flour until no white remains.
Whisk in broth and cream and cook until thickened, about 3-4 minutes. Taste and adjust seasonings as desired.
In a large, greased baking dish (9x13"), combine cooked egg noodles, sauce, frozen peas and carrots and cooked chicken.
Crush crackers in a medium zip top bag. Stir in 1 tablespoon butter and sprinkle over the top of the casserole.
Bake at 350 degrees F for 20 minutes or until bubbly (to prep ahead, simply prepare up to the point of the crackers and top with crackers just before baking).