Preheat the oven to 350°F. Line a baking sheet with parchment paper.
In a large bowl, mix together the peanut butter, brown sugar, egg, baking soda, salt, and vanilla extract until combined.
Using a teaspoon, scoop out the dough and roll into 1-inch balls. Place the balls on the prepared baking sheet, pressing down slightly to flatten.
Bake for 10-12 minutes, or until the cookies are golden brown. Allow to cool on the baking sheet before transferring to a wire rack to cool completely.
Interesting Facts
Peanut butter cookies were first created in the late 19th century.
Peanut butter cookies are a popular snack in schools, as they require few ingredients and are easy to make.
Peanut butter is a great source of protein, so these cookies make for a healthy snack.