Preheat your oven to 375°F (190°C) and line a muffin tin with paper liners or grease it lightly.

In a large mixing bowl, combine the flour, sugar, baking soda, and salt, mixing well to ensure the dry ingredients are evenly distributed.

In a separate bowl, whisk together the melted butter, milk, and vanilla extract until fully combined.

Pour the wet ingredients into the dry ingredients and gently mix until just combined. Be careful not to overmix, as this can result in tough muffins.

Fold in the blueberries, ensuring they are evenly distributed throughout the batter.

In a small bowl, mix the softened cream cheese until smooth. You can add a spoonful of muffin batter to the cream cheese and mix again to lighten it.

Scoop a tablespoon of muffin batter into each muffin cup, then add a dollop of the cream cheese mixture on top. Finally, cover with another tablespoon of the muffin batter, ensuring the cream cheese is hidden.

Bake in the preheated oven for 20–25 minutes, or until a toothpick inserted into the center comes out clean and the tops are lightly golden.

Allow the muffins to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.