Blast off with this sweet deal from SONIC Drive-In on Sept. 30. The popular fast-food chain is serving up 50% off its popular Master Blasts and SONIC Blasts at participating locations. There is a limit of two per customer — small or medium size only. Unlike its other promos, you must ask for the deal, when ordering. Master Blasts are premium shakes made with real vanilla ice cream and lots of extras mixed in. Choose from Triple Chocolate, Turtle Peca, Pineapple Upside Down, Banana Split, Caramel Brownie, Waffleberry Brownie, Malted Brownie Bliss, Strawberry Pucker Pie and Chocolate Chip Cookie Dough. The SONIC Blasts are a little less decadent with just one ingredient mixed in, including Snickers, OREO cookie pieces, BUTTERFINGER candy, M&Ms chocolate candies or Reese’s Peanut Butter Cups. You’re definitely going to need a spoon to dig into the cool savings.