Mix mayonnaise, Italian seasoning, garlic and onion powders in a small bowl until thoroughly combined. Set aside.
Place toasted bread slices on plates or serving platter. Spread each slice with herbed mayonnaise. Top with slices of bacon, romaine, tomatoes and avocado.
Heat butter in large nonstick skillet over medium-high heat. Add eggs and cook for 2 to 3 minutes. Flip eggs and cook an additional 1 to 2 minutes for desired egg doneness. Remove eggs and place one on each BLT sandwich.
Salt and pepper to taste; serve immediately.
Poached Egg Variation: Crack egg into a small cup and gently slide egg into simmering water. Stir gently to help egg white retain its shape. Simmer 3 minutes until whites are cooked through. Remove egg with slotted spoon; drain as much water as possible. Place poached egg on each sandwich and sprinkle with black pepper and salt to taste. Repeat with remaining eggs.