Preheat oven to 350 F and line a baking sheet with parchment paper.
In a medium bowl, combine flour, pumpkin pie spice, baking soda and salt.
In the bowl of an electric mixer fitted with the paddle attachment, beat butter and sugar on medium-high until light and fluffy, about 2-3 minutes.
Beat in egg until well combined.
With the mixer on low speed, add molasses, buttermilk and dry ingredients alternately in 3 parts, beginning and ending with the dry ingredients, beating just until incorporated.
Drop tablespoons of batter onto the prepared baking sheet.
Place into the oven and bake until the edges are golden brown but the center is still moist, about 10-12 minutes.
Remove from the oven and cool completely on a wire rack before frosting.