Coolhaus custom-built sandwiches, named after famous architects, are sold in supermarkets across the country, as well as from trucks in Los Angeles, New York, Austin, and Dallas. Now the owners part with the recipes for their coolest creations, like the BuckMINTster Fuller (Dirty Mint Chip Ice Cream with Chocolate Chip Cookies) and the Frank Behry (Strawberry Gelato with Snickerdoodles). Daring flavors range from classic (Cookies and Sweet Cream),...