Chunky Monkey Oatmeal Cookie Skillet (Printable)

Warm banana chocolate walnut oatmeal baked in a cast-iron skillet

# What You’ll Need:

→ Dry Ingredients

01 - 1 1/2 cups old-fashioned rolled oats
02 - 1 cup all-purpose flour
03 - 1/2 teaspoon baking soda
04 - 1/2 teaspoon salt
05 - 1/2 teaspoon ground cinnamon

→ Wet Ingredients

06 - 1/2 cup unsalted butter, melted and slightly cooled
07 - 1/2 cup light brown sugar, packed
08 - 1/4 cup granulated sugar
09 - 1 large egg
10 - 2 teaspoons vanilla extract
11 - 2 medium ripe bananas, mashed

→ Mix-Ins

12 - 1/2 cup semisweet chocolate chips
13 - 1/2 cup chopped walnuts
14 - 1/4 cup unsweetened shredded coconut, optional

# How-To Steps:

01 - Preheat oven to 350°F. Lightly grease a 10-inch cast-iron skillet with butter or nonstick spray.
02 - In a large bowl, whisk together oats, flour, baking soda, salt, and cinnamon.
03 - In a separate bowl, combine melted butter, brown sugar, and granulated sugar. Whisk until smooth.
04 - Add egg and vanilla extract to the wet mixture and whisk well. Stir in mashed bananas until fully combined.
05 - Pour wet mixture into dry ingredients and mix until just incorporated.
06 - Gently fold in chocolate chips, walnuts, and coconut if using.
07 - Spread dough evenly into the prepared cast-iron skillet.
08 - Bake for 20 to 24 minutes, or until the top is golden and the edges are set but the center remains slightly soft.
09 - Let cool for 10 minutes before serving warm. Serve slices directly from the skillet, optionally topped with ice cream.

# Expert Hints:

01 -
  • It's naturally sweetened by ripe bananas, so you don't feel guilty eating it straight from the skillet at 10 p.m.
  • The cast iron does something magical—the edges crisp up while the center stays fudgy, like you somehow nailed it on your first try.
  • One pan, one bake, and suddenly you have dessert that feeds a crowd or lasts you through the week.
02 -
  • Brown sugar clumps if it's old—break them up before measuring or your dough will have pockets of intense sweetness and dryness in other spots.
  • Overmixing after the wet meets the dry is the number-one reason this comes out tough instead of tender; fold gently and stop when you still see a few streaks of flour.
  • Don't skip the cooling time or the center will be soup when you slice it; that 10 minutes makes all the difference between beautiful slices and falling apart.
03 -
  • Toast your walnuts in a dry pan for 3 to 5 minutes before chopping—it deepens their flavor and makes them taste less raw and more intentional.
  • If your bananas aren't quite ripe enough, a squeeze of honey or maple syrup in the wet mixture compensates and adds complexity.
  • Cover the skillet loosely with foil if the top is browning too quickly before the center is done; it's a simple save that happens more often than you'd think.
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