Tear American cheese slice into several pieces; distribute pieces over tortilla.
Scatter sliced scallions, bacon bits and shredded cheddar cheese over tortilla.
Place the skillet over medium-low to low heat; cover loosely with foil while preparing eggs.
Immediately melt butter in small nonstick skillet over medium heat.
Break eggs into a small bowl or cup; add salt and pepper if desired; whisk to combine.
Pour eggs into skillet with melted butter; cook, stirring occasionally from bottom.
*Note: The goal for the eggs is to be cooked, but not overcooked, and scrambled but gathered together toward the end to form a cohesive "log" (see photo.) Turn the log over once in skillet to assure all of the egg is cooked.
Remove foil from skillet with prepared tortilla; place cooked egg "log" in center of tortilla; fold tortilla over egg, burrito style (see photos.)
Serve immediately or wrap in wax paper for eating on the run.