Chunky Monkey Oatmeal Cookie Skillet (Printable)

Golden oatmeal skillet with bananas, chocolate chips, and walnuts baked in cast-iron for a warm, shareable dessert.

# Ingredient List:

→ 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 for enhanced richness

# Directions:

01 - Preheat oven to 350°F. Grease a 10-inch cast-iron skillet or oven-safe pan 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 to maintain texture.
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, or until edges are golden and a toothpick inserted in center comes out mostly clean with a few moist crumbs acceptable.
09 - Let cool for 10 minutes before serving. Serve warm directly from skillet, optionally topped with vanilla ice cream.

# Expert Tips:

01 -
  • It bakes in one pan and comes straight to the table looking impressive without any fussy plating.
  • The texture is that sweet spot between chewy cookie and thick brownie that keeps people coming back for seconds.
  • Banana and chocolate together feel indulgent but the oats make it feel almost reasonable.
02 -
  • Banana-based batter can feel almost too moist—this is normal and actually prevents dryness in the final cookie, but watch the bake time carefully near the end or it becomes cake.
  • The skillet will stay hot long after it comes out of the oven, so place it on a trivet or heat-safe surface and warn people before they touch the handle.
03 -
  • Toast your walnuts in a dry skillet for 3 to 4 minutes before chopping—this deepens their flavor and makes them taste fresher than raw pieces.
  • Mash your bananas with a fork until mostly smooth but slightly chunky; this creates better flavor distribution than blending them into oblivion.
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