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

Line up 6 pieces of heavy-duty aluminum foil, each large enough to wrap an apple completely. Lightly crumple and then flatten each piece so it’s easy to mold snugly around the apples later.

Wash and dry the apples. Use an apple corer or a small paring knife to carefully core each apple, removing the stem and seeds but leaving the bottom intact so the filling doesn’t leak out.

In a small bowl, stir together the softened butter, brown sugar, and ground cinnamon until you have a thick, sandy paste.

Place one cored apple in the center of a sheet of foil. Stuff a spoonful of the butter-sugar mixture into the hollow center, pressing it down gently. Add about 2 teaspoons of raisins or chopped walnuts on top of the filling, then finish with a little more of the butter-sugar mixture if there’s room. Repeat with the remaining apples and filling.

Wrap each apple tightly in its foil, bringing the sides up and around the apple and pinching at the top to seal. You want them snug so the buttery juices stay inside and steam the apples.

Arrange the foil-wrapped apples upright in a single snug layer in the bottom of a dry slow cooker, packing them close together so they help support one another.

Cover the slow cooker with its lid. Cook on LOW for 3 1/2 to 4 1/2 hours, or until the apples are very tender when pierced with a knife but still holding their shape. The exact time will depend on the size and firmness of your apples and the heat of your slow cooker.

Turn off the slow cooker and let the apples rest, still wrapped, for about 10 minutes. This helps the hot juices settle a bit so they don’t all spill out at once.

To serve, carefully lift each foil packet out of the slow cooker with tongs or a spatula. Place on small dessert plates or shallow bowls. Open the foil away from your face to avoid the burst of hot steam, then gently peel it back to reveal the apple and its spiced syrup.

Serve the apples warm, spooning any buttery cinnamon sauce from the foil over the top. Add ice cream or whipped cream if you like, and enjoy right away while the kitchen still smells like Sunday at Grandma’s.

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.