Consider, if you will, a light-as-air citrus-edged genoise layered with a delicate grapefruit mousse and topped with torched peaks of meringue; or a crisp, flaky tart lined with bittersweet chocolate and billowing with coconut cream; or a custardlike brioche pudding crowned with macerated peaches; or a dense, dark, fudgelike brownie of crisp whole walnuts and premium Scharffen Berger chocolate. The patissiers at Tartine create some of the most toothsome, ethereal pastries east of the Pacific Ocean in a friendly old worn-wood establishment with big communal tables and picture windows looking out on 18th Street. Their croissants, scones, éclairs, tarts, cookies, and cakes -- not to mention an array of savories that includes a quiche made of Niman Ranch ham, crème fraîche, and seasonal produce -- are made with a gossamer touch as well as organically raised ingredients from local suppliers. The always-busy coffee bar in back offers Mr. Espresso java, Straus Family Creamery addenda, and (why not?) two dozen wines by the glass, any of them ideal alongside a rectangle of Valrhona devil's food cake with caramel and chocolate ganache.