Set a 6-well jumbo silicone muffin pan on a baking sheet; each well should hold at least 3/4 cup.

Melt 1 1/2 cups chocolate chips or wafers in 20 to 30-second microwave bursts, stirring between bursts. If needed, add coconut oil 1 teaspoon at a time, up to 1 tablespoon, following package directions for wafers. Reserve half of the melted chocolate for the tops.

Divide the coating half among the 6 wells, starting with about 1 tablespoon per well. Spread over the bottoms and up the sides to the planned filling height. Chill 5 to 10 minutes until firm, then patch thin spots with the rest of the coating portion and chill until firm.

Mix 1 1/2 cups graham cracker crumbs, 1/2 cup peanut butter, 3 tablespoons melted butter, and 1 pinch salt. Divide evenly among the 6 coated wells and press gently into an even layer. Refrigerate about 10 minutes.

Divide 7 ounces marshmallow creme evenly among the 6 crusts, spooning or piping it in. Smooth gently and leave room below the chocolate rims for the lids. Chill about 10 minutes.

Divide the reserved half of the melted chocolate over the 6 fillings, letting it cool to barely warm first. Spread to meet the side coating. Rewarm briefly if necessary, then cool again before covering the creme.

Top the 6 cups with up to 1 tablespoon graham crumbs and 18 mini marshmallows, if using. Refrigerate 30 to 45 minutes until completely firm. Peel the silicone away gently while supporting each cup.

For toasted toppings, toast the 18 mini marshmallows separately on a heatproof surface with a culinary torch, away from paper liners. Let cool, then add to the cups.