Place a medium saucepan on the stove and add the peanut butter, honey, and brown sugar. Warm over medium heat, stirring constantly, until the mixture is smooth, glossy, and just starting to bubble, about 2-3 minutes.
Remove the saucepan from heat and stir in the vanilla extract and a pinch of salt, mixing until fragrant and well combined.
Add the oats to the saucepan and stir vigorously until the oats are fully coated and the mixture is thick and sticky. If it feels too loose, add a bit more oats; if too dry, add a splash of warm water.
Using a tablespoon or small scoop, portion out the mixture onto a parchment-lined baking sheet. Gently flatten each cookie with the back of a fork or spatula to about 1.5 cm thickness.
Sprinkle a tiny pinch of salt or some chocolate chips on top of each cookie if desired, then let the cookies rest at room temperature for about 20 minutes to set. For quicker results, pop them in the fridge for 15-20 minutes.
Once the cookies are firm and slightly glossy, carefully transfer them to a plate or container. Serve immediately or store in an airtight container at room temperature for up to a week.
