Heat oven to 350°F. Spray large cookie sheet with CRISCO® Original No-Stick Cooking Spray, or grease with shortening. Remove dough from both cans; place seam side down and 3 inches apart on cookie sheet. Cut 4 or 5 diagonal slashes (1/2-inch deep) with sharp knife on top of each loaf. Bake 26 to 30 minutes or until deep golden brown. Cool slightly while preparing meatballs, about 25 minutes.
Spread the oil in bottom of 13x9-inch (3-quart) glass baking dish. Reserve 1 teaspoon of the taco seasoning mix for sauce; place remaining seasoning mix in large bowl. Add remaining meatball ingredients; mix well. Shape mixture into 1-inch balls; place in baking dish. Bake uncovered 25 to 30 minutes, turning meatballs once halfway through baking, until meat thermometer inserted in center of meatballs reads 160°F.
Meanwhile, in food processor, place all sauce ingredients; process until smooth. Set aside.
Set oven control to broil. Cut each loaf in half horizontally, cutting to but not completely through one long side; place cut side up on cookie sheet. Broil 5 to 6 inches from heat 1 to 2 minutes or just until lightly toasted.
Spread 1/4 cup sauce on each toasted cut side. Spoon hot meatballs evenly onto bottom halves of loaf. Top evenly with toppings. Drizzle with remaining sauce. If desired, close sandwiches. Cut each sandwich in half. Serve immediately.