Monster Cookies

a top down image of a tray of monster cookies

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These Monster Cookies are soft, chewy, crunchy and full of delicious peanut butter flavour! This easy recipe makes a big batch, so enjoy some now, freeze some for later. These truly are the best monster cookies!


Units Scale
  • 3 large eggs
  • 1 cup brown sugar
  • 1 cup white sugar
  • 1 tsp vanilla extract
  • 1 tsp corn syrup
  • 2 tsp baking soda
  • 1/2 tsp salt
  • 1/2 cup butter (melted)
  • 1 1/2 cup creamy peanut butter
  • 4 1/2 cups old fashioned rolled oats
  • 1/2 cup all purpose flour
  • 2/3 cup Reese’s Pieces (peanut butter)
  • 2/3 cup chocolate chips


  1. Preheat your oven to 350 degrees F.
  2. Using a stand mixer with the paddle attachment, combine the eggs, sugars, vanilla, corn syrup, baking soda and salt.
  3. Add in the peanut butter and melted butter. Make sure to scrape the sides of the bowl and mix well.
  4. Add the flour, and oats. Combine.
  5. Then add in the Reese’s Pieces and chocolate chips, but mix these in by hand so they don’t break.
  6. Drop these as 2 heaping tablespoon balls onto a parchment paper lined baking sheet (you can use a cookie scoop to shape them). About 8 to a tray, and flatten the cookie dough balls slightly.
  7. I added some candy eyeballs and extra Reese’s Pieces to the tops of the unbaked cookies for decoration.
  8. Bake for 11-12 minutes. I like mine a bit chewy, but if you like your cookies harder, bake for 12-15 minutes.
  9. Let the cookies cool on the pan for about 5 minutes before transferring them to a wire rack.