Preheat oven to 350 degrees.
In a medium saucepan over medium heat, stir together first 7 ingredients (chili powder through garlic).
Cook sauce for 10 minutes then remove from heat and set aside.
In a large skillet over medium heat, add ground beef and onion; cook, crumbling beef, for 10 minutes or until beef has browned and onion is tender.
Remove from heat and set aside.
Cut cabbage in half and remove core.
Carefully peel off cabbage leaves then fill each with about 1/4 cup of ground beef/onion mixture and roll up.
Place cabbage rolls, seam sides down, in a large baking dish.
Pour sauce over the top and bake for 15 to 20 minutes or until cabbage is tender. Serve warm.