Add the cream cheese, granulated sugar, and vanilla extract to a bowl and mix it together until smooth.
Place the filling in a piping bag.
Mix and divide the muffin batter into the 12 cupcake liners.
Place the piping bag in the middle of the muffin batter and squeeze the cream cheese filling into the muffin while slowly lifting the piping bag up until you reach the top.
Top the muffins with the cinnamon sugar and bake them for 7 minutes at 400-450F.
Then reduce the heat to 350F and bake for 10-12 minutes.
To check when they are done, insert a toothpick in the muffin. If it comes out with no residue, your muffins are done.
Let muffins cool in the pan on a wire rack for 5 minutes before taking them out, then let them cool until satisfied.