1. Preheat the oven to 350 degrees F (177 degrees C). Line a baking sheet with parchment paper.

2. Place the peanut butter, egg, Besti, vanilla (if using), and salt (if using) in a food processor. Process until smooth, scraping down the sides if needed.

3. Pulse in the peanut pieces, if using, until just combined. (Don't overmix – you want some pieces left for crunch.)

4. Use a medium cookie scoop to place balls of dough onto the prepared cookie sheet. Press the cookie dough into the scoop tightly before releasing onto the sheet. Flatten using a fork in a criss-cross pattern. Between cookies, dip the fork in a cup with cold water and then wipe with a paper towel. (This will prevent sticking.)

5. Bake for about 15-20 minutes, until very lightly golden. Cool completely before handling. Cookies will become crisp as they cool.

Serving size: 1 2-inch cookie