When I think of layer cake, images of smiling, neatly coiffed, white-aproned 1950s housewives come to mind. I think of childhood birthday parties, the Pillsbury dough boy, the red Duncan Hines cake box, and tubs of store-bought icing in pastel colors. It certainly doesn't seem to fit in with the images I've got swirling around San Franciso dessert menus: all homemade ice cream, seasonal pies, and tight-rope walking flavor experiments sprinkled with salt. I can't help but get excited when a layer cake shows up at a dinner out. They're few and far between, so let's take a look at the restaurants and bake shops around town that are taking the sentimental layer cake for a spin.