1. Preheat the oven to 375°F and line a muffin tin with paper liners or grease it lightly.
2. In a mixing bowl, combine flour, sugar, baking powder, and cinnamon. Set aside.
3. In another bowl, whisk together melted butter, milk, eggs, and vanilla until well combined.
4. Gradually mix the wet ingredients into the dry ingredients until just combined; do not overmix.
5. In a small bowl, beat softened cream cheese with powdered sugar and a little vanilla until smooth.
6. Fill each muffin cup halfway with the batter.
7. Add a spoonful of the cream cheese filling into the center of each muffin cup.
8. Cover the cream cheese filling with more batter, filling each cup about three-quarters full.
9. In a separate bowl, mix sugar and cinnamon for the topping.
10. Sprinkle the cinnamon sugar mixture generously over each muffin.
11. Bake for 18-20 minutes, or until muffins are golden brown and a toothpick inserted into the batter (not the filling) comes out clean.
12. Allow the muffins to cool slightly before serving warm for the best gooey texture.
13. Optionally, drizzle with vanilla cream or melted white chocolate for extra indulgence.
14. Store leftovers at room temperature for 2-3 days or freeze for up to 3 months.