Pour half of the pasta sauce into baking dish. Add half of the remaining pesto, and spread the sauce in an even layer in bottom of dish. Sprinkle remaining mini meatballs over top. Using spoon, fill each jumbo pasta shell with cheesy mini shells, placing each jumbo shell in bottom of baking dish as you go. Once you have 1 layer of shells, pour remaining pasta sauce over shells. Then pour remaining pesto over shells. Now continue to fill remaining jumbo shells with cheesy pasta, placing them right on top of the first layer of jumbo shells.