Heat tortillas according to package directions; keep warm.
Cook bacon in a large nonstick skillet until crisp; remove bacon, and drain on paper towels, reserving 1 tablespoon drippings in skillet. Crumble bacon, and set aside.
Cook hash browns and onion in hot drippings over medium-high heat, stirring often, 10 minutes or until lightly browned and onion is tender.
Whisk together eggs, salt, and pepper.
Pour into skillet, and cook, stirring gently, over medium heat 8 to 10 minutes or until eggs are cooked. Remove from heat, and stir in bacon.
Spoon egg mixture evenly down centers of tortillas, and top with cheese, if desired. Fold opposite sides of tortillas over filling, and serve immediately. Serve with salsa, if desired.