1/2 tablespoon baking soda
1 egg, lightly beaten
1 tsp all-purpose flour
1 tsp vanilla extract
Heat oven to 350°F. Coat several large baking sheets with cooking spray.
Combine peanut butter, brown sugar, baking soda, and ¼ tablespoon salt in a bowl.
Add egg and vanilla extract and beat until smooth.
Shape dough into 24 balls and arrange on prepared pans.
Dip tines of a fork into flour and gently press a crisscross pattern into the top of each cookie.
Bake until lightly browned on the bottom, 10 to 12 minutes. Transfer to a rack to cool.
Store in airtight container at room temperature.