Christmas has its own smell, and most of it comes out of the oven. A loaf of stollen on the kitchen counter, oliebollen frying on New Year's Eve, a tray of biscuits cooling on a rack. Glass Christmas ornaments shaped like bread and pastry catch a little of that warmth. A mouth-blown macaron, a stack of poffertjes in glass, a slice of bread with sprinkles hanging quietly in the branches.