This is the peanut butter cookie built on the classic flourless formula — just peanut butter, sugar, egg and a little baking soda, so the peanut flavor comes through clean instead of diluted by flour.
The fork crosshatch is more than decoration — it flattens the thick dough evenly so the centers actually bake through.
Let the cookies cool on the pan for a few minutes before moving them — this flourless dough is fragile while hot and can crumble if handled too soon.
Save this recipe for later — pin it to your cookies board.
In a bowl, stir together peanut butter, sugar, egg, baking soda, vanilla and salt until a smooth dough forms.
Roll the dough into 1-inch balls. Roll in extra sugar if desired, then place on a lined baking sheet spaced 2 inches apart.
Preheat oven to 350°F (175°C). Press each ball flat with a fork in a crosshatch pattern. Bake for 9-11 minutes until the edges are just set.
Let cool on the baking sheet for 5 minutes before transferring to a wire rack — they're fragile straight out of the oven.
The peanut butter itself provides enough structure to hold the cookie together, which is what makes this version simpler than a flour-based peanut butter cookie — it also gives a denser, more intensely peanut-flavored result.
Beyond tradition, the crosshatch flattens the dough ball evenly so it bakes through consistently — without flattening, a thick ball of this dense dough can stay raw in the center.
Natural peanut butter (the kind that separates) works but can make the dough oilier and less consistent — stir it very thoroughly before measuring, or stick with a no-stir creamy peanut butter for the most reliable texture.