Beat together peanut butter, egg, vanilla and salt.
When thoroughly mixed and combined, add in the sweetener and blend until completely incorporated.
Store mixture in refrigerator for at least a half hour.
Preheat oven to 350 degrees F.
Remove dough from refrigerator and roll into small balls, approximately an inch in diameter.
Place them on a parchment lined cookie sheet, about 3 inches apart.
With a fork, stamp them down creating a criss-cross pattern.
Bake for roughly 10-12 minutes, until they turn golden brown (they will be soft).
Remove from oven and cool COMPLETELY (failure to do so will make these crumble to dust).