Creating breakfast croissant sandwiches is simple if you follow these straightforward steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C).

1. Prepare Croissants: Slice each croissant in half and place them on a baking sheet.

1. Cook Eggs: In a medium bowl, whisk the eggs with salt and pepper. Pour the mixture into a non-stick skillet over medium heat and scramble until just set. Remove from heat.

1. Add Cheese: Sprinkle the shredded cheese over the scrambled eggs and allow it to melt for about 1 minute.

1. Layer Fillings: On the bottom half of each croissant, layer 2 slices of bacon, a couple of spoonfuls of the scrambled egg and cheese mixture, and a few slices of avocado and fresh spinach.

1. Top and Bake: Place the other half of the croissant on top. Spread a little butter on the top for extra flavor. Bake in the preheated oven for 10-15 minutes or until the croissants are golden and crispy.

1. Serve Immediately: Remove from the oven and let cool for a minute before serving.

1. Garnish: Optionally, you can serve with a side of fresh fruit or a light salad.