Microwave Marshmallows: Place marshmallows on a microwave-safe plate, arranged in a single layer with space between each one. Heat the marshmallows on high for 60 to 90 seconds. Let them sit for five minutes to harden.
Oven Method: Preheat oven to 350 degrees Fahrenheit. Arrange marshmallows on a clean baking sheet in a single layer. Place the baking sheet in the oven, turn off the heat, and leave the marshmallows in the oven for 10 to 15 minutes. Let them cool and harden in the air or in the refrigerator.
