Chunky Monkey Oatmeal Cookie Skillet (Printable Version)

Golden oatmeal cookie skillet with banana, chocolate chips, and walnuts baked in cast iron for shareable dessert.

# What You’ll Need:

→ Dry Ingredients

01 - 1½ cups old-fashioned rolled oats
02 - 1 cup all-purpose flour
03 - ½ teaspoon baking soda
04 - ½ teaspoon baking powder
05 - ¼ teaspoon salt

→ Wet Ingredients

06 - ½ cup unsalted butter, melted
07 - ⅓ cup light brown sugar, packed
08 - ⅓ cup granulated sugar
09 - 1 large egg
10 - 1 teaspoon pure vanilla extract

→ Chunky Monkey Add-ins

11 - 2 ripe bananas, mashed (approximately 1 cup)
12 - ½ cup semisweet chocolate chips
13 - ½ cup chopped walnuts
14 - ½ cup chopped dark chocolate, optional

# Step-by-Step Guide:

01 - Preheat oven to 350°F. Grease a 10-inch cast-iron skillet with butter or nonstick spray.
02 - In a medium bowl, whisk together oats, flour, baking soda, baking powder, and salt. Set aside.
03 - In a large bowl, combine melted butter, brown sugar, and granulated sugar. Mix until well combined and creamy.
04 - Beat in egg and vanilla extract, then stir in mashed bananas until fully incorporated.
05 - Gradually fold dry ingredients into wet mixture until just combined. Do not overmix.
06 - Gently fold in chocolate chips, walnuts, and chopped dark chocolate if using.
07 - Spread batter evenly into prepared skillet.
08 - Bake for 22 to 25 minutes, until edges are golden and a toothpick inserted in center comes out mostly clean with a few moist crumbs acceptable.
09 - Cool for 10 minutes before serving. Serve warm directly from skillet, optionally topped with vanilla ice cream.

# Additional Tips::

01 -
  • It bakes in one pan, so theres no scooping dough or rotating trays halfway through.
  • The banana keeps it soft and fudgy in the center while the edges turn golden and crisp.
  • It feeds a crowd without any fuss, and everyone loves tearing into a warm skillet with their forks.
  • You get all the flavors of a smoothie bowl but in chewy, chocolatey cookie form.
02 -
  • Don't overbake this or it will turn dry and crumbly instead of soft and chewy, so pull it out when the center still jiggles just a little.
  • Use bananas that are really ripe, almost black-spotted, because underripe bananas won't mash smoothly and won't add enough sweetness.
  • Let the melted butter cool for a minute before adding the egg, or the egg will scramble and leave you with weird lumps.
03 -
  • Toast the walnuts in a dry skillet for a few minutes before adding them to the dough, it deepens their flavor and makes them taste almost buttery.
  • Press a few extra chocolate chips and walnut pieces on top of the dough right before baking so the finished skillet looks bakery-perfect.
  • If your skillet runs hot, check the cookie at 20 minutes to avoid overbaking, every oven is a little different and you want that soft center.
Go Back