You can swap the mini pretzels for 2 1/2 cups of crushed graham crackers, vanilla wafers, or even cornflakes for a different kind of crunch; just keep the butter amount the same so the topping toasts nicely.
If you prefer a little less sweetness, use dark chocolate chips and add a light sprinkle of flaky sea salt over the top right after baking. For a s’mores-style version, use graham cracker pieces instead of pretzels and add a handful of extra chocolate chips during the last 5 minutes of baking.
To make this dessert nutty, stir 1/2 cup chopped pecans or walnuts into the pretzels before spreading them on top of the fluff. Food safety tips: marshmallow fluff is safe to eat straight from the jar, but once baked, this dessert will be very hot in the center—always let it cool before serving, especially to children, to avoid burns from the molten sugar.
Store leftovers tightly covered in the refrigerator for up to 3 days, and rewarm portions gently in the microwave or a low oven until just soft and gooey again; discard if you notice any off smells, mold, or if it has been left out at room temperature for more than 2 hours in a warm
