Much like time and mastodon hairstyles, yogurt is easier to manipulate when frozen. Put the freeze on icy shenanigans with today’s Groupon: for $10, you get $20 worth of frozen yogurt at BTO Self Serve Yogurt. Today's deal is only redeemable at the North Cortaro and Sunset Drive locations. BTO Self Serve offers health-conscious dessert devotees the opportunity to twirl and top their own chilly creations. Grab a cup and fill it with enough reduced-fat frozen yogurt ($0.39/oz.) to douse five alarm-mouth fires. Each day offers tongues 12–16 different choices from a rotating line-up of more than 30 flavors, ranging from palette-pleasing pistachio and lip-smacking green apple to classics like chocolate and cookies 'n' cream. Once you've chosen a frosty foundation, accessorize it with a treasure trove of crunchable toppings, such as rainbow sprinkles, pineapple, brownie bites, and oxygen. Lactose-intolerant indulgers, or those who just disagree to disagree with it, can tickle their taste buds with an assortment of dairy-free flavors, including vanilla, chocolate, and mango.