Cook the bacon using your preferred method—either air-fry it at 400°F for about 8-10 minutes or bake in the oven at 400°F for 15-20 minutes until crisp. Let cool and chop into small pieces.

In a medium pot, bring water to a gentle boil. Carefully add large eggs and simmer for 9 minutes. Transfer eggs to a bowl of ice water to cool.

Once cooled, gently crack and peel the eggs under cold running water. Discard yolks from three eggs and chop remaining eggs into bite-sized pieces.

In a large mixing bowl, combine chopped eggs with scooped avocados, green onions, Greek yogurt, lemon juice, Dijon mustard, salt, pepper, and cayenne pepper.

Toast slices of whole wheat bread until golden brown.

Assemble sandwiches by spreading the avocado egg salad on toasted bread, layering with bacon, tomatoes, and spinach, then top with another slice of bread.