Prep Ahead: Measure out all your ingredients before starting. This recipe comes together quickly, so you’ll want everything ready to go.
Prepare Baking Sheets: Line two cookie sheets with parchment paper.
Cook the Base Mixture: In a 3-quart saucepan, melt the butter over medium heat. Stir in the sugar and milk, and whisk until the mixture is smooth. Bring it to a boil and cook for about 1 ½ minutes, stirring occasionally.
Important: The mixture needs to reach 230°F to set properly. Use a candy thermometer or instant-read thermometer if possible. If you don’t have one, 1 ½ minutes at a steady boil on medium heat should do the trick.
Mix the Cookie Dough: Remove the pan from the heat. Stir in the peanut butter, salt, vanilla extract, and oats. Mix until fully combined.
Scoop and Shape: Use a cookie scoop or spoon to drop 2-tablespoon-sized portions onto the lined baking sheets.
Let Set: Let the cookies sit at room temperature until firm, or place them in the fridge to set more quickly.
Tips & Variations:
You can use creamy or crunchy peanut butter—just avoid natural kinds with oil separation.
Chopped nuts or mini M&Ms make great mix-ins if you want to switch things up.
Using a thermometer helps guarantee perfect texture every time.