Add softened Grassland butter and pumpkin puree into a standard mixer. Combine. Once combined, add the powdered sugar and mix on low speed.
Add in milk, and beat on medium speed until frosting has become thinner and more creamy.
Add the vanilla and mix until combined. Then add the cinnamon and nutmeg.
Transfer the mixture to a piping bag to add to your favorite treat. We tried pumpkin shaped cookies!