Preheat the oven to 350F then line a baking sheet with parchement paper and set aside.
Cream the butter, granulated sugar, and brown sugar together until light and creamy. Add in the egg, vanilla extract, and molasses, and mix until smooth.
½ cup butter, ¼ cup granulated sugar, ¼ cup brown sugar, 1 large egg, ½ teaspoon vanilla extract, 2 tablespoon molasses
Gently mix in the flour, corn starch, baking powder, baking soda, spices, and salt.
1 & ⅔ cup all purpose flour, 1 tablespoon corn starch, ½ teaspoon baking powder, ¼ teaspoon baking soda, 1 teaspoon cinnamon, 1 teaspoon ground ginger, ¼ teaspoon ground cloves, ¼ teaspoon salt
Scoop out equally sized cookie dough balls, place them on the baking sheet and flatten it to about 1 inch in thickness.
Bake in the preheated oven for 12 minutes. Let the cookies cool on the baking sheet for 20 minutes before transferring to a cooling rack to cool fully.
Top each cookie with the homemade buttercream and decorate with your favorite sprinkles.