Bake Sale Peanut Butter Oat Bars. Think a doughy, buttery peanut butter cookie base made with old-fashioned oats, baked until just set, then layered with creamy peanut butter. On top, a rich chocolate frosting is poured over the bars to sandwich in all that peanut butter goodness. Once the frosting sets, it creates that old-fashioned crackly icing we all know and love. These bars are chocolatey, peanut buttery, and so delicious!

I’m back today with even more bake sale–inspired treats. I’m honestly not even sure if bake sales are still much of a thing, but I love baking up sweets that are perfect for sharing this time of year.

Bake sale or not, these are the bars to bring for game day, family parties, or dinners with friends. It’s that time of year when everyone’s starting to gather again after a summer of fun and easy nights.

Inspired by the peanut butter oat bars our school lunchroom used to serve, these are guaranteed to be a hit with everyone. And if you do end up baking them for the school bake sale, they’ll definitely be the first treat to disappear.

These are the details

Ingredients 

• salted butter
• creamy peanut butter – crunchy will work too!
• brown sugar
• vanilla
• eggs
• vanilla extract
• flour
• old-fashioned oats
• baking soda

For the Icing

• powdered sugar
• cocoa powder
• vanilla
•  dark or milk chocolate – I love dark

Special Tools

For these peanut butter bars, you need two mixing bowls and an electric mixer.

The Steps

Step 1: Make the cookie dough

In a mixing bowl, beat the butter together with the brown sugar, peanut butter, and vanilla. Add the eggs and beat until combined. Mix in the flour, oats, baking soda, and salt.

Mix, mix, mix until you have a soft dough!

Step 2: Bake

Line a 9×18-inch baking dish with parchment paper. Or, if you prefer thinner bars, use a slightly larger sheet pan.

Bake for about 20 minutes (22 minutes if using a sheet pan), until just set.

Step 3: The peanut butter layer

As soon as the bars come out of the oven, spread the remaining peanut butter evenly over the top. The heat from the bars will melt the peanut butter, making it easy to spread into a smooth layer.

Let the peanut butter stiffen and set. To speed things up, pop the pan in the fridge or freezer until firm.

Step 4: The chocolate icing

Whisk together the powdered sugar, cocoa powder, vanilla, and melted milk chocolate until smooth and fudgy. Pour the icing over the bars and spread evenly.

Let the icing set and harden, or dig in right away while it’s still gooey—so delish!

Tip

If you’d like a shiny, glossy finish to your icing, whisk in a couple teaspoons of meringue powder. It helps the frosting set without smudging. Totally optional, but a fun extra!

Whether it’s back-to-school, game day, or just a family night in, these bars are the perfect dessert to bake, share, and enjoy. And if you’ve got kids around, this is an easy recipe they can help with too!

Looking for easy “lunchroom” style back-to-school desserts? Here are a few ideas: 

Crinkle Top Brownies

Chocolate Peanut Butter Pretzel Blondies

Giant Salted Espresso Hot Fudge Cookies

Lastly, if you make these Bake Sale Peanut Butter Oat Bars, be sure to leave a comment and/or give this recipe a rating! Above all, I love to hear from you guys and always do my best to respond to each and every comment. And of course, if you do make this recipe, don’t forget to tag me on Instagram! Looking through the photos of recipes you all have made is my favorite!

Toasted Marshmallow Mashup Cookies. Think soft and chewy chocolate chip cookies, but with a mashup twist—oats for heartiness, salty pretzel bits for crunch, melty dark chocolate, and gooey toasted marshmallows swirled throughout. They’re sweet, salty, buttery, extra gooey, a little toasty, with just the right amount of addicting. Perfect for game day gatherings or those back-to-school bake sales. These are the cookies that will disappear first!

With both school bake sales and football season on the horizon, I figured cookies were a must. Last year I shared my toasted caramel marshmallow rice krispie treats—do you guys remember those? So many of you still make them on repeat, and they’re always a hit.

Now, I’ll be honest—marshmallows are not usually my go-to ingredient. I don’t love them…unless they’re toasted. Toasted marshmallows? Completely different story. Gooey, golden, just the right amount of caramelized. And in my mind, a little goes a long way. These cookies are exactly how I love them—soft, chocolatey, gooey, with that irresistible marshmallow toastiness.

I’m so excited to finally share these with you—they just might become your new fall favorite cookie!

Here are the Cookie Details

Step 1: Gather your ingredients

You’ll need the basics: butter, dark brown sugar, flour, baking powder, baking soda, and sea salt. Simple, simple—nothing fancy, but all good things.

Now for the stir-ins, which are the most important part! Grab old-fashioned oats, salted pretzel twists, pecans, semi-sweet or dark chocolate chips, and of course, marshmallows—the real magic in these cookies.

Step 2: Mix the dough

Start with soft butter and beat it together with the dark brown sugar and vanilla. Add in 2 whole eggs plus 1 extra yolk.

Next, mix in the flour, baking powder, baking soda, and salt. Stir in the oats, crushed pretzels, chopped pecans, and chocolate chips until just combined. These are best eaten warm, right out of the oven, so keep that in mind as you mix!

Step 3: Toast the marshmallows

To do this quickly, I use the broiler. Arrange the marshmallows on a baking sheet and broil until golden and toasty.

My one very important note here—do not walk away from the oven. Every broiler cooks differently, but they all toast FAST. Marshmallows can go from white to black in seconds, so watch closely.

Once toasted, gently fold the marshmallows into the cookie dough. They don’t need to be fully mixed in—just a few swirls of gooey marshmallow are perfect.

Step 4: Bake

Scoop the dough into ¼ cup-sized balls (these are big cookies!). Arrange no more than 6 per baking sheet to give them plenty of space.

Because they’re large, they’ll need a bit more oven time. Bake at 350 for 8 minutes, then rotate the pans and bake for another 4–5 minutes, until just set. Remove from the oven and let the cookies rest on the baking sheet to finish cooking.

They’ll be gooey, golden, and looking so delicious. Enjoy one warm—or package them up for your next bake sale or game day. Guaranteed crowd-pleasers!

Some notes

• These cookies will spread—so be careful not to overcrowd the baking sheet! The result is slightly crisp edges with perfectly gooey centers (just like the photos).

• For a slightly thicker cookie, skip the extra egg yolk and stick with only 2 eggs. They won’t spread as much but will still be soft and delicious.

• Sticky marshmallows giving you trouble? Dampen your hands with water and wipe them dry—this trick makes handling the dough so much easier.

Looking for easy party desserts? Here are a few ideas: 

Chewy Chocolate Peanut Butter Bars

Crinkle Top Brownies

Chocolate Peanut Butter Pretzel Blondies

Homemade Vegan Peanut Butter Twix Bars

Caramel Butter Cake with Fudgy Chocolate Frosting

Retro-Style Chocolate Sheet Cake

Toasted Marshmallow Caramel Rice Krispie Treats

Lastly, if you make these Toasted Marshmallow Mashup Cookies, be sure to leave a comment and/or give this recipe a rating! Above all, I love to hear from you guys and always do my best to respond to each and every comment. And, of course, if you make this recipe, don’t forget to tag me on Instagram! Looking through the photos of recipes you all have made is my favorite!