Step 1: Prepare the Muffin Batter

1. Preheat your oven to 375°F (190°C) and grease a 12-cup muffin tin or line with muffin liners.
2. In a large bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, and sugar.
3. In another bowl, whisk the egg, milk, vanilla extract, and melted butter until smooth.
4. Pour the wet ingredients into the dry ingredients and gently mix until just combined. Be careful not to overmix!

Step 2: Bake the Muffins

1. Divide the batter evenly into the muffin cups, filling each about ¾ full.
2. Bake for 15-18 minutes or until a toothpick inserted into the center comes out clean.
3. Let the muffins cool in the pan for 5 minutes, then transfer to a wire rack.

Step 3: Coat with Cinnamon Sugar

1. In a small bowl, mix the sugar and cinnamon for the coating.
2. Brush each warm muffin with melted butter, then roll in the cinnamon sugar mixture until fully coated.

Step 4: Serve & Enjoy!

Enjoy these muffins warm, or let them cool completely before storing. They taste just like French toast in muffin form—soft on the inside with a crisp, sweet coating!