01 - Preheat oven to 375°F. Line a 12-cup muffin tin with paper liners or grease thoroughly.
02 - In a large mixing bowl, whisk together flour, sugar, baking powder, baking soda, salt, and cinnamon until well distributed.
03 - In a separate bowl, whisk eggs, milk, melted butter, and vanilla extract until fully incorporated.
04 - Add wet mixture to the dry ingredients, stirring gently just until combined. Avoid overmixing to maintain tenderness.
05 - In a small bowl, mix shredded mozzarella and softened cream cheese until evenly blended.
06 - Spoon batter into each muffin cup, filling halfway. Place 1 tablespoon of cheese mixture in the center, then top with remaining batter until cups are about three-quarters full.
07 - Bake for 18–20 minutes, or until a toothpick inserted into the edge of a muffin (avoiding the cheese center) comes out clean.
08 - While muffins bake, combine 1/4 cup sugar and 1 teaspoon cinnamon in a small bowl for the topping.
09 - Once muffins have cooled for 5 minutes, brush the tops lightly with melted butter and sprinkle with cinnamon sugar mixture.
10 - Enjoy warm for optimal flavor and texture.