Expand your taco constructing skills and double your taco delight with this easy and super-satisfying recipe. Cook ground beef and refried beans separately, each with taco seasoning. While you warm crisp taco shells in the oven, make a guacamole of avocado, sour cream, lime juice and salt and pepper. Spread flour tortillas with warm refried beans, then wrap around a crisp shell. Inside the hard shell, layer in the ground beef with Cheddar cheese, shredded lettuce, tomato, onion, sour cream and guac. Get the recipe for Double Decker Tacos.