Preheat oven to 350°F (175°C). Line a baking sheet with parchment paper.

Whisk flour, pumpkin spice, and salt in a medium bowl. Set aside.

In a large bowl, beat butter, cream cheese, granulated sugar, and brown sugar until light and fluffy.

Mix in the egg yolk and vanilla until smooth.

Add the dry ingredients, stirring until just combined into a soft dough.

Scoop 2 tablespoons of dough, roll into balls, then coat in sugar. Place on baking sheet.

Use the back of a tablespoon to press a deep well into each dough ball.

In another bowl, whisk egg, brown sugar, salt, pumpkin spice, milk, pumpkin purée, and vanilla until smooth.

Spoon filling into cookie wells, almost to the top.

Bake 14–17 minutes, until bottoms are golden and filling is set.

Cool 5 minutes on the baking sheet, then transfer to a wire rack. Serve at room temperature.