Place rack in center of oven then preheat to 400 degrees. Meanwhile, lightly coat baking sheet with non-stick spray then set aside. Place ground beef into a large mixing bowl, add onion then set aside.
In a small bowl, whisk together milk, eggs, bouillon, pepper and Worcestershire sauce until the eggs are well beaten and the bouillon has dissolved. Pour the liquid mixture over the beef then mix until combined.
Add breadcrumbs into the beef mixture then mix until they are evenly distributed and the mixture is thick.
Roll the meat into golf ball-sized meatballs, place onto prepared baking sheet then bake 18–20 minutes until nicely browned. For uniform balls you can use a medium cookie scoop or 2 Tbsp per meatball.
While the meatballs bake, combine chili sauce, cranberry sauce, minced garlic and crushed red pepper into a large skillet, stirring until combined. Cook on low heat then let sauce begin heating.
Remove meatballs from oven then transfer them to the pan, leaving behind any fat that has accumulated. Stir to coat the meatballs in the sauce then let them simmer in sauce for at least 1 hour before serving.
If you are serving these at a party, transfer to a slow cooker and set to low for an hour. Let your guests help themselves. Enjoy!
Notes
The cranberry sauce gives this dish a tart, sweet flavor while the chili sauce, garlic and red pepper flakes add a savory, spicy kick!