Chunky Monkey Oatmeal Cookie Skillet

Featured in: Sweet & Simple Treats

This warm, shareable dessert combines the classic flavors of banana, chocolate, and walnuts in a cozy skillet format. Old-fashioned oats create a hearty texture, while melted butter and brown sugar ensure edges bake up golden and slightly crisp. Ripe mashed bananas keep the center tender and naturally sweet. Semisweet chocolate chips melt throughout, and chopped walnuts add satisfying crunch. The entire bakes in one cast-iron pan for easy cleanup and rustic presentation. Serve straight from the oven with vanilla ice cream for the ultimate warm-and-cold contrast. Ready in just 40 minutes with only 15 minutes of active preparation.

Updated on Sun, 08 Feb 2026 08:29:00 GMT
Warm, gooey Chunky Monkey Oatmeal Cookie Skillet with melted chocolate chips and chopped walnuts served straight from the pan. Save
Warm, gooey Chunky Monkey Oatmeal Cookie Skillet with melted chocolate chips and chopped walnuts served straight from the pan. | dashnosh.com

A friend texted me a photo of a blended smoothie one afternoon—bright yellow, topped with whipped cream—and asked if I could somehow make those flavors into something warm and shareable. That night, I found myself standing at my stove with a cast-iron skillet, mashing bananas and thinking about how dessert doesn't always have to be complicated. The result was this golden, chunky cookie that tastes like a Chunky Monkey smoothie decided to become something you could actually sink a fork into. It's the kind of dessert that disappears faster than you'd expect, especially when it's still warm from the oven.

My sister brought her new partner over for dinner last month, and I wasn't sure what dessert would feel casual enough for a first visit but impressive enough to matter. I pulled this skillet out of the oven just as we finished eating, and watching their faces when they realized it was warm, chocolatey, and meant to be shared straight from the pan—that's when I knew this recipe had found its moment.

Ingredients

  • Old-fashioned rolled oats: They give the cookie body and texture without making it dense; don't swap for instant oats or you'll lose that pleasant chewiness.
  • All-purpose flour: This is your structural backbone, so measure it right by spooning and leveling rather than scooping straight from the bag.
  • Baking soda and baking powder: Together they create lift and a slight tang that balances the sweetness of the banana and chocolate.
  • Unsalted butter, melted: Melted butter distributes more evenly and creates a tender crumb; cold butter leaves dense pockets.
  • Brown sugar and granulated sugar: The combination gives caramel notes and proper moisture retention throughout the bake.
  • Ripe bananas: They should be soft enough to mash easily, with brown speckles showing their sweetness has peaked; underripe bananas will taste starchy.
  • Semisweet chocolate chips: These melt slightly as the skillet bakes, creating pockets of chocolate without overpowering the other flavors.
  • Walnuts: Toast them lightly in a dry pan before chopping if you want their flavor to pop, though raw works fine in a pinch.

Instructions

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Prep your oven and skillet:
Heat your oven to 350°F and grease a 10-inch cast-iron skillet thoroughly with butter or spray; cast iron distributes heat evenly and gives you those beautiful golden edges.
Combine the dry team:
Whisk together oats, flour, baking soda, baking powder, and salt in a medium bowl, making sure there are no lumps hiding in the corners. Set this aside and forget about it for now.
Build the wet base:
In a larger bowl, stir melted butter with both sugars until the mixture looks creamy and well blended. This step takes just a minute but creates the foundation for everything that follows.
Add the binding elements:
Crack in your egg, add vanilla, then mash in the bananas until you don't see streaks of yellow anymore. The banana should be mostly smooth with just a few small lumps.
Bring it together gently:
Fold the dry ingredients into the wet mixture slowly, stirring just until you don't see flour streaks; overmixing develops gluten and creates a tough cookie instead of a tender one. It's okay if there are a few flour pockets—keep stirring gently.
Add the chocolate and nuts:
Fold in the chocolate chips, walnuts, and optional dark chocolate pieces with a few gentle strokes, being careful not to crush or break them apart too much.
Transfer to the skillet:
Spread the batter evenly across your prepared skillet, using a spatula to smooth the top without pressing down hard. You want it level but not compacted.
Bake until golden:
Slide into your preheated oven for 22 to 25 minutes; you'll know it's ready when the edges are golden brown and a toothpick inserted near the center comes out with a few moist crumbs clinging to it. A few wet crumbs are perfect—that means it stayed tender instead of drying out.
Cool and serve:
Let the skillet sit on the counter for about 10 minutes so the structure sets, then serve it warm right from the pan with vanilla ice cream if you're feeling indulgent.
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A freshly baked Chunky Monkey Oatmeal Cookie Skillet topped with vanilla ice cream melting over golden, banana-infused edges. Save
A freshly baked Chunky Monkey Oatmeal Cookie Skillet topped with vanilla ice cream melting over golden, banana-infused edges. | dashnosh.com

There's something about pulling a warm, fragrant skillet out of the oven and knowing you're about to share it with people you care about that feels like cooking at its best. This dessert became my answer to the question of how to make something feel homemade without spending hours in the kitchen.

Banana Ripeness Matters More Than You Think

I've made this cookie with bananas at every stage of ripeness, and the difference is real. Spotted, soft bananas give you sweetness and moisture, while barely-yellow ones taste starchy and leave the cookie dry. If your bananas aren't quite there yet, let them sit on the counter for a day or two rather than using them too early. One afternoon I got impatient and used bananas that were still mostly yellow, and the skillet came out tasting vaguely banana-flavored instead of generously banana-flavored.

Cast Iron vs. Other Pans

Cast iron is my preference here because it conducts heat beautifully and gives you those crisp, caramelized edges that make every bite feel special, but a regular 10-inch round cake pan or an oven-safe skillet works too. Just know that aluminum pans brown faster, so you might need to reduce your baking time by a minute or two and keep a closer eye on it. The skillet also means you can bring it straight to the table, which feels like a moment.

Making It Your Own

This recipe has a solid foundation, but it also welcomes tinkering. I've swapped the walnuts for pecans on days when that's what I had in the pantry, added a small handful of dried cherries for tartness, and once even stirred in some shredded coconut because it seemed like a fun idea. The beauty of a skillet cookie is that small changes don't derail the whole thing; they just make it slightly different and entirely yours.

  • For a vegan version, use melted coconut oil instead of butter and make a flax egg by mixing 1 tablespoon ground flaxseed with 2.5 tablespoons water and letting it sit for five minutes.
  • Pecans, hazelnuts, or even chopped almonds work beautifully in place of walnuts, or omit them entirely if you're serving someone with a tree nut allergy.
  • A handful of dark chocolate chunks stirred in alongside the chips gives you pockets of even richer chocolate flavor without overpowering the banana.
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Golden-brown Chunky Monkey Oatmeal Cookie Skillet baked in a cast-iron pan with rich dark chocolate and ripe bananas. Save
Golden-brown Chunky Monkey Oatmeal Cookie Skillet baked in a cast-iron pan with rich dark chocolate and ripe bananas. | dashnosh.com

This skillet cookie sits at that perfect intersection of easy and impressive, warm and shareable, simple and special. Make it once and you'll understand why it keeps getting asked for.

Kitchen Q&A

Can I make this skillet ahead of time?

Yes, you can prepare the batter up to 24 hours in advance and store it covered in the refrigerator. Bake when ready to serve, adding 2-3 extra minutes to the baking time if baking cold.

What if I don't have a cast-iron skillet?

Any 10-inch oven-safe pan works well, including cake pans, pie dishes, or ceramic baking dishes. Adjust baking time as needed—shallow pans may bake faster.

Can I substitute quick oats for old-fashioned rolled oats?

Old-fashioned oats provide the best texture, but quick oats will work in a pinch. The final result may be slightly softer and less chewy.

How should I store leftovers?

Cover tightly and store at room temperature for up to 2 days. For longer storage, refrigerate for up to 5 days. Reheat individual portions in the microwave for 20-30 seconds.

Can I freeze this skillet?

Yes, bake and cool completely, then wrap tightly in plastic and foil. Freeze for up to 3 months. Thaw overnight at room temperature and reheat at 350°F for 10-15 minutes.

Why are my edges burnt but the center is underdone?

This usually means the oven is too hot or the skillet is too close to the heating element. Use an oven thermometer to verify temperature and place the skillet on the center rack.

Chunky Monkey Oatmeal Cookie Skillet

Warm banana chocolate walnut oatmeal skillet baked to golden perfection in a cast-iron pan.

Prep Duration
15 min
Cook Duration
25 min
Complete Duration
40 min
Created by Tyler Morgan

Recipe Type Sweet & Simple Treats

Skill Level Easy

Cultural Heritage American

Output 8 Portion Size

Nutritional Categories Meat-Free

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

01 ½ cup unsalted butter, melted
02 ⅓ cup light brown sugar, packed
03 ⅓ cup granulated sugar
04 1 large egg
05 1 teaspoon pure vanilla extract

Mix-ins

01 2 ripe bananas, mashed (about 1 cup)
02 ½ cup semisweet chocolate chips
03 ½ cup chopped walnuts
04 ½ cup chopped dark chocolate, optional

Method

Step 01

Prepare the Pan: Preheat oven to 350°F. Grease a 10-inch cast-iron skillet with butter or nonstick spray.

Step 02

Combine Dry Ingredients: In a medium bowl, whisk together oats, flour, baking soda, baking powder, and salt. Set aside.

Step 03

Mix Wet Base: In a large bowl, combine melted butter, brown sugar, and granulated sugar until creamy.

Step 04

Incorporate Egg and Banana: Beat in egg and vanilla extract, then stir in mashed bananas until fully incorporated.

Step 05

Combine Wet and Dry: Gradually fold dry ingredients into wet mixture until just combined. Do not overmix.

Step 06

Add Mix-ins: Gently fold in chocolate chips, walnuts, and dark chocolate if using.

Step 07

Transfer to Skillet: Spread batter evenly into prepared skillet.

Step 08

Bake: Bake for 22 to 25 minutes until edges are golden and a toothpick inserted in the center comes out mostly clean.

Step 09

Cool and Serve: Cool for 10 minutes before serving warm from the skillet. Top with vanilla ice cream if desired.

Kitchen Tools Needed

  • 10-inch cast-iron skillet or oven-safe baking pan
  • Mixing bowls
  • Whisk
  • Rubber spatula
  • Measuring cups and spoons

Allergy Alerts

Review ingredients carefully for potential allergens and seek professional medical guidance if concerned.
  • Contains wheat and gluten
  • Contains eggs
  • Contains milk from butter and chocolate chips
  • Contains tree nuts from walnuts

Nutrition Details (serving size)

Numbers shown are estimates only - consult healthcare providers for specific advice.
  • Energy: 310
  • Fats: 15 g
  • Carbohydrates: 41 g
  • Proteins: 5 g