Mix flour, sugar, baking powder, and salt together.
Whisk egg and milk in separate bowl.
Combine wet and dry ingredients gently.
Add melted butter to pancake batter.
Heat pan over medium heat.
Pour 1/4 cup batter per pancake.
Cook until bubbles form on surface.
Flip pancakes and cook other side.
Keep pancakes warm while preparing filling.
Scramble eggs in same pan.
Add bacon and heat through.
Place filling on one pancake half.
Fold pancake over like a taco.
Top with cheese and green onions.
Serve immediately while hot.