Bake the meatballs for 25 minutes, until they are cooked through. Remove the pan from the oven and allow to cool.
While the meatballs are cooling, combine the ketchup, brown sugar, liquid smoke, and garlic in a bowl. After mixing the sauce ingredients together, pour the mixture into a large resealable freezer bag.
Once the meatballs are cool, transfer them to the freezer bag with the sauce and gently mix to coat meatballs in sauce. Remove excess air and seal. Freeze.
Thaw.
To prepare in the crockpot, transfer the meatballs and sauce to the slow cooker. Cook for 2 to 3 hours on high or 5 hours on low.
Thaw.
Preheat the oven to 350°. Place the meatballs and sauce in a baking dish and cover. Bake for one hour, removing the cover for the last 15 minutes.