01 -  Whisk eggs, milk, salt, and black pepper together in a mixing bowl until well combined; set aside. 
 02 -  In a large skillet set over medium heat, cook bacon until crisp; transfer to paper towels to drain. Once cooled, crumble into small pieces. 
 03 -  Discard excess bacon fat, leaving 1 tablespoon in the skillet. Add diced onion and bell pepper; sauté for 2 to 3 minutes until softened. Add chopped spinach and cook until wilted, about 1 minute. 
 04 -  Pour prepared egg mixture over vegetables in the skillet. Gently stir and cook until eggs are just set but still tender. Remove from heat and fold in cheddar cheese and crumbled bacon. 
 05 -  Heat tortillas in a dry skillet or microwave for about 20 seconds until soft and pliable. 
 06 -  Divide the egg filling evenly among tortillas. Top with diced tomato, salsa, and avocado if desired. 
 07 -  Fold in the sides of each tortilla, then roll up tightly to enclose the filling. 
 08 -  For a golden finish, place rolled burritos seam-side down in a dry, hot skillet for 1 to 2 minutes until the tortillas are lightly crisped. 
 09 -  Serve burritos immediately and garnish with hot sauce, if preferred.