Oven-Baked Frito Pie - this is so good

1 lb. lean ground beef
1 can (16 oz) chili beans
1 can (8 oz) tomato sauce
1 can (15 oz) diced tomatoes
1 envelope low sodium taco seasoning
1 cup shredded cheddar cheese (2% fat kind)
3 1/2 cups corn chips (Fritos)
1 1/4 cup fat free sour cream

-Cook ground beef until meat is browned; drain. Stir in beans, tomato sauce, diced tomatoes, taco seasoning mix and 1/4 c. of cheese. Sprinkle 1 cup corn chips in bottom of 8x8 baking dish. Cover with chili. Bake at 350 for 20 minutes. Spread sour cream over chili. Top with remaining corn chips and cheese. Bake 4-5 minutes longer.