Costco has quietly added a sweet treat to its food court menu. The Double Chocolate Mint Sundae is made with mint soft serve layered with chocolate cookie crumbles and chocolate sauce, swirled into a mint-green-and-brown tie-dye. If you aren’t into chocolate, you can order just the mint ice cream. The sundae is slowly making its way across stores nationwide and is expected to be available for a limited time only. The treat will only set you back $2.99.