Step 1
Preheat oven to 350˚F. Line cookie sheets with parchment. If oil has separated from the peanut butter, stir until all oil is mixed in and peanut butter has a smooth consistency.
Step 2
In a large bowl, whisk together sugar, baking soda, and sea salt. Add peanut butter and beaten egg and stir with a large spoon until combined. Stir in chopped peanuts. The dough will be crumbly.
Step 3
Using a medium cookie scoop, drop 11/2-inch balls on prepared sheets, spacing them 2 inches apart. With the bottom of a glass or back of a spoon, flatten the balls to 1/2-inch thickness.
Step 4
Bake for 12 to 15 minutes, until golden brown. Lightly sprinkle with fine grain sea salt, if desired. Cool completely on cookie sheets.
Step 5
Store cookies in an airtight container for up to 1 week.
Step 6
Baker's Notes: Cashew butter is sometimes less moist than peanut butter. If you substitute cashew butter, you may want to add 1/4 teaspoon vegetable oil prior to mixing.