In a large bowl, combine 15 ounces can tomato sauce, 1 cup sour cream, 1 teaspoons onion powder, 2 teaspoons garlic powder, 2 teaspoons Italian seasoning, 1 teaspoon salt, and ½ teaspoon pepper. Stir through half of the 2 cups cheese.
Cook pasta
Cook 1 lb pasta shells in salted boiling water until tender. Drain.
Cook the ground beef
In a large skillet heat 1 tablespoon olive oil and cook 1 lb ground beef until browned.
Assemble
Add the cooked pasta and the tomato sauce & sour cream mixture to the skillet with the ground beef and mix well.
Pour into a 9 x 13 baking dish
Bake
Bake 20 minutes at 375°F, the remove and add the remaining cheese.
Continue to bake another 10 to 15 minutes until cheese is melted and slightly browned on top.