Preheat oven to 350°F. (180 ºC)
In a small bowl, use an electric mixer to cream peanut butter and brown sugar until fluffy. Beat in the egg.
Add oats and baking soda to creamed mixture, and mix well. Use your hands to make a ball, it’s rather crumbly, but do not worry, just knead it and it will eventually form a ball.
Line baking sheet with parchment paper.
Roll dough into 2-inch balls, and press to flatten on the cookie sheet.
Bake for 8-10 minutes or until the cookies turn slightly brown.
Cool cookies on a rack, and store leftovers in an airtight container.
Sourced from the Internet – but adapted by Esme’s kitchen