Grandma’s secret weapon for Sunday dinner. Just 5 ingredients wrapped tight. The smell when you crack open the foil changes everything.

For a nutty crunch, swap the raisins for chopped pecans or almonds, or use a mix of dried fruit and nuts in the center. If you like a deeper flavor, add a pinch of ground nutmeg or cloves to the butter-sugar mixture, but keep the cinnamon as the star so the apples shine. For a lighter version, you can reduce the butter to 3 tablespoons and the brown sugar to 3–4 tablespoons total, dividing it thinly among the apples; they’ll be less saucy but still fragrant and soft. If you’re cooking for adults, a teaspoon or two of apple brandy or bourbon drizzled into each apple before wrapping adds a quiet warmth. Very large or very firm apples may need closer to 5 hours on LOW, while smaller apples may be ready in about 3 hours—check one apple early, rewrapping if it needs more time. Leftovers keep well in the refrigerator for a couple of days; store them in their foil packets in a container, then reheat gently in the slow cooker or in a low oven until warmed through.