Preheat your oven: Set your oven to 350°F (175°C) and line a muffin pan with paper liners or grease them lightly.
Prepare the cream cheese filling: In a small bowl, beat the cream cheese until smooth. Add a tablespoon of sugar (optional) and set aside.
Combine dry ingredients: In a large bowl, whisk together flour, baking soda, salt, and cinnamon.
Mix wet ingredients: In another bowl, combine the pumpkin puree, sugar, vegetable oil, and eggs. Mix until well blended.
Combine the mixtures: Gradually add the wet ingredients to the dry ingredients, stirring gently until just combined. Avoid over-mixing.
Fill the muffin cups: Spoon about 1 tablespoon of the muffin batter into each cup. Add about a teaspoon of the cream cheese mixture on top, then cover with another tablespoon of batter.
Bake: Place in the oven and bake for 20-25 minutes or until a toothpick comes out clean from the muffin. Let them cool in the pan for 5 minutes before transferring to a wire rack.