Recipe

Cake Mix Cookie Bars

Chewy centers, crisp edges, and a one-bowl dough you can customize with whatever is in the pantry.

By Matt Campbell

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4.8

A pan of thick, chewy cake mix cookie bars cut into squares on a light kitchen counter with a small stack of bars on a plate nearby

Cake mix is basically a little box of baking shortcuts, and I mean that as a compliment. When you want something sweet today, but you do not want to pull out three kinds of flour and a scale and your emotional support stand mixer, cake mix steps in like a reliable friend with a spare phone charger.

These cake mix cookie bars are my favorite way to use it because they are faster than cookies, harder to mess up, and they hit all the important notes: chewy middle, crisp edges, and enough butter to make the whole kitchen smell like you actually tried. Pick your mix-ins and call it a win.

Cake mix, eggs, butter, and vanilla arranged on a kitchen counter ready to bake

Why It Works

One bowl, low drama: no electric mixer required, just a sturdy spoon or spatula.
Texture you can control: a slightly underbaked center gives you that chewy, bakery-style bite.
Endless flavor swaps: change the cake mix flavor, swap chips, add nuts, or go full sprinkle mode.
Great for crowds: bars cut cleanly and travel well, so they are potluck friendly.

Pairs Well With

Storage Tips

Room temperature: Store bars in an airtight container for up to 4 days. If you want them extra chewy, a small piece of sandwich bread in the container often helps. Replace the bread if it gets dry.

Refrigerator: Not required, but you can refrigerate up to 7 days for a firmer, fudgier bite. Let sit 15 minutes before serving.

Freezer: Freeze individual bars wrapped tightly, then placed in a freezer bag for up to 2 months. Thaw at room temp, or microwave 10 to 15 seconds for that warm-cookie-bar moment.

Common Questions

Can I use any flavor of cake mix?

Yes. Yellow, chocolate, funfetti, strawberry, spice, lemon. They all work. Most standard U.S. boxes are around 15.25 ounces, but brands vary (often 13.25 to 15.5 oz). If yours is smaller, the bars can turn out a little drier. If it is larger, they can be softer or a bit greasy. They will still be tasty, just keep an extra-close eye on bake time.

Do I prepare the cake mix according to the box?

Nope. Use the dry cake mix straight from the box. The eggs and butter in this recipe are the only liquids you need.

Why is my batter so thick?

That is normal. This is closer to cookie dough than cake batter. Use a sturdy spatula and press it into the pan. If it feels impossibly thick, your butter may have cooled too much. Let the bowl sit for 5 minutes, then try again.

Can I make these without eggs?

You can. Swap in 2 flax eggs (2 tablespoons ground flax + 5 tablespoons water, rested 5 minutes). Texture will be a bit softer and the bars may brown differently. You may also need an extra 1 to 3 minutes in the oven.

How do I know when they are done?

Look for golden edges and a center that looks set but still a little soft. A toothpick should come out with moist crumbs, not wet batter. Overbaking is the main way to lose that chewy center.

Can I use a 9x9-inch pan?

Yes. The bars will be a little thinner, so they bake faster. Start checking at 15 to 17 minutes. Pull them when the edges are lightly golden and the center looks set.

Can I double the recipe?

Yep. Double all ingredients and bake in a 9x13-inch pan. Start checking around 22 minutes and expect 22 to 28 minutes depending on your oven, mix-ins, and pan. Metal pans bake faster than glass, so check early if you are using metal.

Matt Campbell

I have always had a huge passion for the culinary arts, people, working as a team, and so on. I wanted to pursue my love for cooking initially at Virginia Commonwealth University with a culinary arts degree; however, I instead decided to apply myself and acquire more practical skills. My end goal is to eventually open my own restaurant or similar establishment.

Kitchen Essentials

8x8-inch metal baking pan (or 9x9-inch, start checking a few minutes early)
Parchment paper (highly recommended for easy lifting)
Large mixing bowl
Rubber spatula or wooden spoon
Measuring cups and spoons
Wire rack for cooling

I love ambitious cooking, but my weekday self is a different person. Weekday Matt wants dessert that feels like a reward for surviving email, dishes, and the mysterious disappearance of every clean spoon. Cake mix bars are my go-to because they taste like you spent way longer than you did, and they give you permission to be a little chaotic with the mix-ins. I have made these with chocolate chips, crushed pretzels, leftover Halloween candy, and once, the last handful of cereal in the box. No regrets.