Popcorn Marshmallow Treats

Ingredients You’ll Need

• 12 cups plain popped popcorn, unpopped kernels removed
• 1/2 cup (113 g) unsalted butter
• 16 oz (454 g) mini marshmallows
• 1 tsp vanilla extract
• 1/2 tsp fine salt
• 1/2 cup extra mini marshmallows, optional

How to Make Popcorn Marshmallow Treats

1. Step 1.

   Line a 9×13-inch pan with parchment and lightly grease it. Put the popcorn in a very large bowl and remove every hard unpopped kernel you can find.

2. Step 2.

   Melt the butter in a large saucepan over low heat. Add the marshmallows and stir just until smooth; do not boil or keep cooking after the last lumps disappear.

3. Step 3.

   Remove from the heat and stir in vanilla and salt. Pour the mixture over the popcorn and fold gently until the popcorn is evenly coated. Fold in the extra mini marshmallows, if using, after the mixture has cooled for about 1 minute.

4. Step 4.

   Transfer to the pan and press into an even layer with lightly greased hands or a sheet of parchment. Press only enough to level the surface; compacting the popcorn makes the finished bars dense.

5. Step 5.

   Cool about 20 minutes, then lift from the pan and cut into 16 squares with a sharp knife.

Soft bars start with low heat

Marshmallows only need enough heat to melt into the butter. Once the mixture is smooth, take it off the stove. Continuing to cook it concentrates the sugar and gives the finished bars a firmer, chewier set than most people want.

Keep the popcorn waiting in a very large bowl before you start melting. The marshmallow binder thickens as it cools, so this is not the moment to hunt for a bowl after the saucepan is ready.

Do not skip the unpopped-kernel check

This is one of those boring steps that matters more than a decorative topping. Once everything is sticky, hard kernels become difficult to spot and unpleasant to bite into. Shake the popped corn around the bowl and pick through the bottom before adding the marshmallow mixture.

How firmly should you press the pan?

Only enough to make an even layer. Use greased hands or parchment and stop when the surface is level. Compressing hard crushes the popcorn and pushes out the air spaces that make the bars lighter than cereal treats.

The same rule applies when cutting: let the slab cool enough to hold together, then use a sharp knife with decisive cuts instead of sawing repeatedly through the popcorn.

Add-ins need a cooling pause

If you want extra mini marshmallows, chocolate candies or small pretzel pieces, wait about a minute after coating before folding them in. Chocolate added to a piping-hot binder can melt into streaks instead of staying distinct. Keep add-ins moderate so the bars still have enough sticky surface to hold together.

Best way to make them for a party

These are at their best the day they are made or the next day. Store airtight at room temperature for up to 2 days. Refrigeration makes the marshmallow binder noticeably firmer, so room-temperature storage gives a better bite unless your kitchen is unusually hot.