A heads-up for travelers with a sweet tooth: If you like doughnuts, fritters, and cakes, Butter Cream Bakery & Diner in downtown Napa should be on the itinerary. The 1950s-style diner (it actually started in 1948) is renowned in the Bay Area for its baked goods, and on busy weekends, customers will line up around the corner for a bag of goodies to take away. The cakes, which start at around $20 apiece, are veritable works of art, and the maple bar doughnut with a strip of honey-cured bacon is always a sell-out. But Butter Cream isn’t just a sweet shop; it’s a greasy spoon, too, complete with grill and griddle specialties such as pancakes, egg sandwiches, tuna melts, and burgers. If you go, go hungry, as portions are tremendous (and, of course, save room for a sweet to end the meal).