In a mixing bowl, cream together the softened unsalted butter and sugar until light and fluffy, about 3-4 minutes. Add the egg and vanilla extract, mixing until fully combined.

In a separate bowl, whisk together the all-purpose flour and salt until evenly combined. Gradually incorporate the dry mixture into the wet mixture, blending until a cohesive dough forms. Cover the bowl with plastic wrap and chill in the refrigerator for 30 minutes.

Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper. Once chilled, roll the dough into 1.5-tablespoon-sized balls and place them on the prepared baking sheet, leaving space between each. Gently flatten each ball and create a small well in the center.

Bake the cookies for 10-12 minutes, or until they are lightly golden around the edges. Allow them to cool completely on a wire rack.

In a bowl, beat the cream cheese until smooth. Gradually mix in the canned pumpkin puree, brown sugar, pumpkin pie spice, and cinnamon, followed by the heavy cream until well combined and fluffy. Chill the filling in the refrigerator for 30 minutes.

Once the cookies have cooled, spoon or pipe the spiced pumpkin filling into the wells of each cookie. Top with whipped cream and a sprinkle of cinnamon or nutmeg.