Add the gelatin to a mixing bowl with 2/3 cup water. Lightly mix or swirl and set aside to let it bloom.
In a saucepan, add the allulose, 1/2 cup water and the vanilla bean paste. Stir continuously for a few minutes until the liquid is bubbling and golden.
Pour the hot liquid into the mixing bowl with the bloomed gelatin. Mix with a stand or hand mixer for about 10 minutes, until fluffy like marshmallow.
Transfer to a container and refrigerate until set, then slice into cubes.
About 150 calories for the entire batch (roughly 9 calories per cube when sliced into 16). From lisa hwang on Instagram.
