In n Out Double Double Animal Style | Copycat Recipes - Check out this In-n-Out Double Double Animal Style Copycat Recipe. It has 2 all beef patties fried in mustard, 4 slices of cheese, animal sauce, pickles, lettuce, and caramelized onions and it's very easy to make!brbrDouble Double IngredientsbrBeef Patties:br1 lb. Ground Beef (best results use 80 20)br8 Slices American Cheese (I used a mild cheddar)br12 cup Yellow MustardbrSalt and Pepper to tastebrbrSecret Sauce:br13 cup mayobr3 Tbsp ketchupbr1.