During autumn, I love the Apple Mille-Feuille at Bouchon Bakery, little rectangles with the scent of caramel and sweet apples. Six layers, three components, two layers of each. There's a flaky housemade mille-feuille pastry; a thin genoise rich with cinnamon and spices; and the apple element, a tiny dice of fresh apples caramelized and cooked down until it practically turns into a jam. A fork will do just fine, but it's small enough that you can pick up the whole thing with your fingers and eat away. (Much more satisfying.)
While you're there, make sure to get another seasonal treat—the Crabapple and Cider Tart. A crumbly moist biscuit base comes topped with cider mousse. The foamy, yolk-rich sabayon base ensure that this particular mousse is airy-light, an effortless, faintly sweet spoonful.