Preheat your oven to 350°F (175°C) and line a muffin tin with paper liners.

In a medium bowl, beat the softened cream cheese and granulated sugar until smooth and creamy. Mix in the egg yolk and vanilla extract until fully incorporated. Set this filling aside.

In a large bowl, whisk together the all-purpose flour, baking soda, salt, and ground spices. Set the dry mixture aside.

In a separate bowl, whisk together the granulated sugar, brown sugar, canned pumpkin puree, vegetable oil, eggs, and vanilla extract until smooth and homogenous.

Gently fold the dry ingredients into the wet mixture until just combined. The batter should be thick but well-integrated.

Spoon the batter into the muffin cups, filling them halfway. Add a dollop of the cream cheese filling in the center and top with more batter until three-quarters full.

Bake for 18-22 minutes, checking for doneness with a toothpick. Allow the muffins to cool in the pan for 5-10 minutes before transferring them to a wire rack.

For the frosting, beat together softened unsalted butter and cream cheese until fluffy. Gradually add sifted powdered sugar, vanilla extract, and a pinch of salt, whipping until light and airy.