Caramel Popcorn with Marshmallow

23 large marshmallows

2 cups brown sugar

¼ cup light corn syrup (such as Karo®)

1 cup butter

1 teaspoon vanilla extract

2 (3.5 ounce) packages microwave popcorn, popped

Cook and stir the marshmallows, brown sugar, corn syrup, butter, and vanilla extract together in a pot over medium-low heat until the marshmallows are completely melted, 5 to 7 minutes.

Put the popcorn in a large bowl; pour the marshmallow mixture over the popcorn and gently stir with a big spoon to coat.