Preheat your oven to 350°F (175°C) and line a muffin tin with paper liners.
In a large bowl, whisk together the flour, baking powder, baking soda, salt, and ground cinnamon.
In another bowl, beat the softened butter, granulated sugar, and brown sugar until light and fluffy.
Add the eggs one at a time, mixing well after each addition, then stir in the vanilla extract.
Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk, and mix until just combined. Do not overmix.
In a separate bowl, mix the softened cream cheese, granulated sugar, and vanilla extract until smooth.
Spoon about 1 tablespoon of muffin batter into each muffin cup, followed by a teaspoon of the cream cheese filling, then top with another tablespoon of muffin batter to cover the filling.
In a small bowl, combine the cinnamon sugar topping ingredients. Sprinkle the cinnamon sugar mixture generously over the tops of the muffins.
Bake for 18-20 minutes or until a toothpick inserted into the center comes out clean.
Allow the muffins to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.
Notes
For added flavor, consider mixing in some chopped nuts or chocolate chips into the muffin batter.
You can also experiment with different spices like nutmeg or pumpkin spice for a seasonal twist.
For a lighter version, substitute half of the cream cheese with Greek yogurt.