Toast slices of bread gently on low setting in a toaster or toaster oven.

In a large skillet over medium heat, melt butter. Add eggs and scramble, stirring constantly, until just set, about 1 minute. Season with salt and pepper, to taste. Remove from heat.

To build the sandwich, top 4 slices of bread evenly with scrambled eggs, cheese, tomatoes and avocado. Season with salt and pepper. Top with bacon and then the remaining bread slices. Slice and serve.