Like its burgers, Blanc's milkshakes are big, rich and intricately flavored. You can also order them spiked. Forget about vanilla. Grown-ups order such sophisticated shakes as the Sangria, the Crème Brûlée and the Gin and Tonic. Made with Foo's Fabulous Frozen Custard and Shatto milk, along with various liquors and liqueurs, the creamy concoctions can pack a slight punch. Priced at about $9, the shakes are big enough to share. And that's good because you can't leave a restaurant with spiked leftovers.