Add ½ cup of water and gelatin powder to a stand mixer’s metal bowl. Let it sit for 10 minutes to bloom.

Line a baking tray or dish with parchment paper. A smaller dish will create thicker marshmallows, while a wider dish will make them thinner.

In a saucepan, combine the remaining ½ cup of water, allulose, and vanilla. Simmer over medium heat for 5 minutes without letting the allulose change color. For caramel-flavored marshmallows, simmer for 10 minutes until the mixture begins to caramelize.

Start the stand mixer on low speed, mixing the gelatin mixture. Slowly pour in the hot allulose syrup while continuing to mix.

Once all of the syrup is incorporated, increase the stand mixer to high speed and whip for about 10 minutes. The mixture will expand and turn white.

Quickly transfer the marshmallow mixture onto the prepared baking tray, spreading it evenly. Leave it uncovered at room temperature for 6 hours before cutting into pieces.

These marshmallows will melt under high heat, just like traditional marshmallows.