Preheat oven to 375°F (190°C). Grease a muffin tin or line with paper liners.
In a medium bowl, combine the flour, sugar, baking powder, and salt. Make a well in the center and add the oil, milk, egg, and vanilla. Stir until just combined.
Fold in the blueberries. Divide the batter among the prepared muffin cups. Place a small amount of cream cheese in the center of each muffin.
Bake for 20 to 25 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Allow the muffins to cool in the tin for 5 minutes before transferring to a wire rack to cool completely.
Interesting Facts
Blueberries are low in calories and are a great source of vitamin C, fiber, and antioxidants.
Cream cheese is a great source of calcium and is high in fat.
These muffins are best served fresh, but can also be frozen for up to 3 months.