1. Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.
2. In a bowl, whisk together flour, pumpkin spice, and salt. Set aside.
3. In a large mixing bowl, beat cream cheese, butter, and sugars until light and fluffy, about 3 minutes.
4. Add the egg yolk and vanilla extract. Mix until combined.
5. Gradually add the dry ingredients into the wet mixture. Fold with a spatula to avoid dry pockets. Dough will be thick.
6. Prepare the filling: In another bowl, whisk pumpkin puree, egg, milk, brown sugar, pumpkin spice, and vanilla until smooth.
7. Scoop dough into 36 g (2 tbsp) balls, roll in coarse sugar, and place 2 inches apart on baking sheet.
8. Press a well in the center of each dough ball using the back of a spoon or a measuring spoon.
9. Fill each well with 1 tbsp of pumpkin filling.
10. Bake 14–17 minutes, until edges are golden and filling is set. Cool on a wire rack.
11. Top with whipped cream before serving, if desired.