While cookies bake, you may clean your mixing bowl and make your frosting. Combine unsalted butter, powdered sugar, vanilla extract, heavy cream, lemon juice (if using), and salt. Beat for about 3 minutes.
Take the remaining frosting and dye it into however many colors you’d like for your pumpkin spice sugar cookies. I wanted a mix of orange and white pumpkins so dyed half of my leftover buttercream orange.
After your cookies have cooled and buttercream is ready, load pumpkin frosting into one piping bag, fitted with a small open round or open star tip. I used tip 32 and switched to 12 halfway through for variety.