3/4 cup unsalted butter, 1 stick melted, 1/2 stick softened
1 cup light brown sugar, packed
2 large eggs at room temperature, lightly beaten
1 cup canned pumpkin
1 tbsp pumpkin pie spice
1 1/2 tsp vanilla
1 tsp baking powder
1 tsp baking soda
3/4 tsp plus 2 pinches salt
1 2/3 cup flour
4 oz cream cheese, chilled
1 cup confectioners sugar
Preheat oven to 350 and line two baking sheets with parchment paper.
In a large bowl, whisk together the melted butter and brown sugar until smooth. Whisk in the eggs, pumpkin, pumpkin pie spice, 1 tsp vanilla, baking powder, baking sugar, and 3/4 tsp salt. Fold in the flour with a spatula.
Scoop 8-12 evenly spaced mounds divided evenly onto the baking sheets. Bake until springy to the touch, about 10 minutes. After being cooked, transfer to a rack to cool completely.
In a large bowl, cream the softened butter with cream cheese with an electric mixer. Add confectioners sugar, 2 pinches of salt, and 1/2 tsp vanilla. Mix on low until blended, then beat on medium-high speed until fluffy, about 2 minutes.
Spread the flat side of the cakes with the frosting and top with another cake.