The departure of Laurent Tourondel hasn't slowed the expansion of the BLT empire, having opened its second fancy burger joint on the Upper East Side. The modern 100-seat eatery borrows from the same crowd-pleasing template as its downtown predecessor, BLT Burger, serving up kobe hot dogs, spiked milk shakes and Angus-beef burgers made from a blend of sirloin, short rib, chuck and brisket. But you'll also find new creations on the uptown menu, including the Hot Diggity (a bacon-wrapped hot dog with frisée and papaya mostarda); the "UltiMELT" (a burger topped with caramelized onions and bacon and sandwiched between two rye-and-Gruyère grilled cheese sandwiches); and the Dark and Frozen milk shake (Gosling's Black Seal Rum, Reeds Ginger Brew and vanilla ice cream).