1. Preheat oven 350 degrees F.

2. Cook pasta shells, rinse, and drain.

3. Brown ground beef in skillet, drain fat.

4. Reduce heat to medium-low, add cream cheese and chili powder. Let simmer for 5 minutes.

5. Toss shells with melted butter, then fill with beef mixure.

6. Arrange filled shells in a 13×9 inch pan. Pour taco sauce over shells and cover with foil.

7. Bake in preheated oven for 15 minutes.

8. Uncover, top with cheeses and crushed chips, then continue to bake for another 15 minutes.

9. Serve topped with sour cream.