For years, I kept a jar of natural, organic, one-ingredient peanut butter in my pantry—wholesome, slightly oily, and always in need of a stir . This was back when I lived in the Hudson Valley, surrounded by health food stores on every corner. Abandoning my beloved Skippy for the all-natural "better" stuff was inevitable. Before I knew it, my grocery tote had filled with maca-dusted goji berry–chia seed–flaxseed granola; grains each more ancient than the last; antioxidant superfoods by the handfuls; and—naturally—a jar of peanut butter made of just peanuts. But once I switched to natural peanut butter, the urge to dig a spoon straight into the jar suddenly disappeared—and with it, one of life's small pleasures. Living in New York City has a way of stripping the pretense from things. Since moving here, I've traded the open greenery of the Hudson Valley for Brooklyn's neighborhood parks and corner bodegas.…