California Smash Burger with Avocado, Bacon, and Ranch from Smashed: 60 Epic Smash Burgers and Sandwiches for Dinner, for Lunch, and Even for Breakfast by Adam Walton and Brett Walton

Ingredients

• 1 tablespoon (15 ml) vegetable oil
• 6–7 ounces (170 to 200 g) 80/20 ground beef, divided into two 3- to 3½-ounce (85 to 100 g) loosely packed meatballs
• 2 teaspoons salt (to taste)
• 2 teaspoons pepper (to taste)
• 2 slices Swiss cheese
• 1 potato hamburger bun
• 2 slices cooked bacon
• 2 tomato slices
• 1 small avocado, thinly sliced
• ½ red onion, thinly sliced
• Ranch dressing, for topping
• additional 1 tablespoon (14 g) mayonnaise, for toasting the buns