Cake Mix Chocolate Chip Cookie Bars (Soft, Chewy & Addictive) – Easy Dessert for Any Day

These cookie bars taste like a bakery treat but come together with a simple box of cake mix. They’re thick, soft, and studded with melty chocolate chips—perfect for parties, bake sales, or a last-minute sweet tooth situation. You’ll love how forgiving and quick the recipe is, and the texture is spot-on: chewy centers with lightly crisp edges.

No mixer needed, and no chilling dough. Just stir, press, and bake.

What Makes This Special

These bars use a cake mix shortcut, which means fewer ingredients, less measuring, and consistently great results. The oil and eggs keep the bars tender, while the cake mix provides a soft crumb that mimics classic cookie bars without the fuss.

You can customize the mix-ins easily—think nuts, toffee bits, or a swirl of peanut butter. They bake up evenly and slice cleanly, making them ideal for sharing. Best of all, they taste like you worked way harder than you did.

Shopping List

• 1 box yellow cake mix (about 15.25 ounces)
• 1/2 cup unsalted butter, melted and slightly cooled (or sub 1/2 cup neutral oil)
• 2 large eggs, room temperature
• 2 teaspoons vanilla extract
• 1 cup semisweet chocolate chips (plus a handful for topping)
• 1/2 cup mini chocolate chips (optional, for extra chocolate in every bite)
• 1/4 teaspoon flaky sea salt (optional, for finishing)
• Nonstick spray or parchment for the pan

How to Make It

1. Prep the pan. Heat the oven to 350°F (175°C).

   Line a 9×9-inch pan with parchment, leaving overhang for easy lifting. Lightly spray the parchment and sides.

2. Melt the butter. Melt the butter in a microwave-safe bowl and let it cool for 3–4 minutes so it doesn’t scramble the eggs.
3. Mix the wet ingredients. In a large bowl, whisk the eggs and vanilla until smooth. Slowly stream in the cooled melted butter, whisking until combined.
4. Add the cake mix. Sprinkle in the cake mix and stir with a spatula until no dry pockets remain.

   The dough will be thick—more like cookie dough than cake batter.

5. Fold in the chips. Stir in the semisweet chips and, if using, the mini chips. Reserve a small handful to press on top before baking for a bakery-style look.
6. Press into the pan. Transfer the dough to the prepared pan. Lightly dampen your fingertips or use a greased spatula to press it into an even layer.

   Scatter the reserved chips on top.

7. Bake. Bake for 20–24 minutes, until the edges are set and lightly golden and the center no longer looks glossy. A toothpick should come out with a few moist crumbs, not wet batter.
8. Optional finish. Sprinkle a pinch of flaky sea salt over the hot bars to balance the sweetness.
9. Cool and slice. Let the pan cool on a rack for at least 30–45 minutes. Lift out using the parchment and cut into 12–16 squares.

   The longer they cool, the cleaner the slices.

Storage Instructions

Store the bars in an airtight container at room temperature for up to 4 days. Add a slice of bread in the container to keep them soft. For longer storage, freeze the cut bars in a single layer until firm, then transfer to a freezer bag for up to 2 months.

Thaw at room temperature or microwave for 10–15 seconds to bring back the just-baked softness.

Health Benefits

These are a treat, but you can make small tweaks for a better balance. Using dark chocolate chips adds antioxidants and a deeper cocoa flavor. Swapping part of the chocolate for chopped nuts brings healthy fats and a satisfying crunch.

You can also use unsweetened shredded coconut or rolled oats (replace up to 1/3 cup of chips) for added texture and fiber. Portion control helps too—cut smaller squares, and you still get the sweet, chewy bite you crave.

What Not to Do

• Don’t overbake. Dry bars are the result of leaving them in too long. Pull them when the edges are set and the center is still soft.
• Don’t skip cooling. Slicing while hot will make them crumble and look messy.

  Letting them rest sets the structure.

• Don’t use hot butter with cold eggs. You’ll end up with curdled bits and a greasy texture. Cool the butter and use room-temp eggs.
• Don’t pack the pan too small. An 8×8 pan makes them too thick and underbaked in the middle. A 9×9 pan or a 9×13 pan (with reduced bake time) works best.
• Don’t overload with mix-ins. More than 1.5 cups total add-ins can make the bars crumbly and dense.

Alternatives

• Different cake mixes: Try chocolate, funfetti, or spice cake for an instant flavor twist.

  Chocolate cake with white chips is especially good.

• Dairy-free: Use oil instead of butter and dairy-free chocolate chips. Line the pan well to prevent sticking.
• Peanut butter swirl: Dollop 1/3 cup warmed peanut butter on top of the batter and swirl with a knife before baking.
• Salted caramel: Drizzle store-bought caramel over the cooled bars and finish with flaky salt.
• 9×13 pan: Double the recipe or bake a single batch for thinner bars. For thinner bars, start checking at 14–16 minutes.
• Gluten-free: Use a gluten-free yellow cake mix and ensure all mix-ins are gluten-free.

FAQ

Can I use oil instead of butter?

Yes.

Use 1/2 cup neutral oil (like canola or avocado). Butter gives a richer flavor, but oil keeps the bars extra soft and moist.

Why is my batter so thick?

That’s normal. This is a cookie bar dough, not a pourable cake batter.

If it seems too stiff to press, lightly wet your hands or spritz a spatula with nonstick spray.

How do I know when they’re done?

The edges should be lightly golden and set, and the center should look matte, not shiny. A toothpick in the center should come out with a few moist crumbs. If it’s wet, give it a couple more minutes.

Can I add nuts or other mix-ins?

Absolutely.

Keep total add-ins around 1 to 1.5 cups. Try chopped walnuts, pecans, toffee bits, or M&M’s. Fold them in with the chocolate chips.

Do I need a mixer?

No.

A spatula or wooden spoon works perfectly. The dough comes together quickly by hand.

What if I only have an 8×8 pan?

You can use it, but extend the bake time slightly and keep an eye on the center. The bars will be thicker, so test for doneness carefully to avoid underbaking.

Can I halve or double the recipe?

Halving is tricky with cake mix measurements.

It’s easier to bake a full batch and freeze extras. Doubling works great in a 9×13 pan; start checking at 20 minutes.

How do I keep the bars soft for days?

Store them airtight with a slice of bread or a few marshmallows in the container. They help maintain moisture so the bars stay chewy.

Final Thoughts

These Cake Mix Chocolate Chip Cookie Bars are the kind of dessert you make once and keep in your back pocket forever.

They’re quick, forgiving, and endlessly adaptable. Whether you stick to classic chocolate chips or dress them up with swirls and add-ins, you’ll get soft, chewy squares that disappear fast. Keep a box of cake mix in the pantry, and you’re always minutes away from a crowd-pleasing treat.