Preheat your oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners or grease well.
In a large bowl, whisk together 1 3/4 cups all-purpose flour, 1 cup sugar, 1 tablespoon pumpkin pie spice, 1 teaspoon baking soda, and 1/4 teaspoon salt.
In another bowl, mix 1 cup pumpkin puree, 2 eggs, 1/2 cup vegetable oil, and 1 teaspoon vanilla extract until smooth.
Fold the wet ingredients into the dry ingredients until just combined. Don't overmix – a few lumps are okay!
For the cream cheese filling, beat 8 oz softened cream cheese with 1/4 cup sugar and 1 egg yolk until smooth.
Fill each muffin cup about 1/3 full with batter. Add a dollop of cream cheese mixture, then top with more batter until cups are about 3/4 full.
Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
Let cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.