Preheat your oven to 350°F (175°C) and line a muffin tin with paper liners.
In a large mixing bowl, whisk together flour, sugar, baking powder, salt, and 1 teaspoon of cinnamon until well combined.
In another bowl, whisk together melted butter, egg, milk, and vanilla extract until smooth.
Pour the wet ingredients into the dry ingredients and mix until just combined. Be careful not to overmix; it’s okay if there are a few lumps.
Fill each muffin liner about 2/3 full with the batter.
Bake in the preheated oven for 15-18 minutes, or until a toothpick inserted in the center comes out clean.
While the muffins are baking, prepare the cinnamon sugar coating by mixing 1/4 cup granulated sugar with 2 tablespoons ground cinnamon in a small bowl.
Once the muffins are done, remove them from the oven and let them cool for about 5 minutes.
While still warm, dip each muffin in melted butter and then roll it in the cinnamon sugar mixture until evenly coated.
Place the coated muffins on a wire rack to cool completely, allowing the sugar to set.
Notes
Arrange the muffins on a decorative platter and serve with chocolate or caramel sauce for dipping.