Preheat your oven to 350°F (175°C) and grease a muffin tin or line with paper liners.
In a large mixing bowl, combine the flour, sugar, baking powder, cinnamon, and salt. Mix well.
In a separate bowl, whisk together the milk, vegetable oil, eggs, and vanilla extract until well combined.
Pour the wet ingredients into the dry ingredients and stir just until combined. Do not overmix.
In another bowl, beat together the softened cream cheese, sugar, vanilla extract, and egg until smooth and creamy. Set aside.
Fill each muffin cup about halfway with muffin batter. Then, drop a spoonful of the cheesecake filling into the center of each muffin.
Top the cheesecake filling with more muffin batter until each cup is nearly full.
In a small bowl, mix together the brown sugar and cinnamon. Sprinkle this mixture over the top of each muffin.
Bake in the preheated oven for 18-20 minutes, or until the muffins are golden brown and a toothpick inserted into the muffin comes out clean.
Allow the muffins to cool in the pan for about 5 minutes before transferring them to a wire rack to cool completely.