Place bacon on bottom of a 6-oz. ramekin or custard cup coated with cooking spray. Pour egg substitute over top. Microwave, uncovered, on high for 30 seconds; stir. Microwave 15-30 seconds or until egg is almost set. Top with salsa; sprinkle with cheese. Microwave just until cheese is melted, about 10 seconds.
Line bottom of bread with spinach. Place egg and bacon over spinach; replace with bread top.