In a large mixing bowl, whip together the milk and butter with an electric mixer on medium speed. Beat for one minute or until mixture is creamy and smooth.
Add canned pumpkin and beat for one minute.
Add powdered sugar, nutmeg, allspice, cinnamon and vanilla. Beat until all the ingredients have mixed.
Transfer the whipped butter into an airtight container. Store in fridge for 7-10 days.