Cook ground beef in a crockpot on low for 2-4 hours. Strain ground beef when cooked. Add taco seasoning & cream cheese into ground beef until mixed thoroughly. Boil your pasta shells for 9 minutes and let them cool. Scoop ground beef mix into pasta shells. (I have found a cookie scoop works great for this!) Lay the shells on a cookie sheet and flash freeze them by placing them into the freezer for 30 minutes or until they seem mostly frozen. When mostly frozen, put into a freezer bag and store in the freezer.
Day Of: Take as many or as few shells as you need. Put shells into an oven-safe pan, no thawing needed! Coat shells liberally with taco sauce and cover with tin foil. Bake covered shells at 350 degrees for 45 minutes. Take shells out after 45 minutes and top with shredded Mexican cheese and crushed tortilla chips. Bake for an additional 15 minutes. Top with sour cream if desired and enjoy!