A cake mix cookie bars recipe is the shortcut every home baker needs when a dessert craving hits but there’s no time for creaming butter and sugar. You stir a box of cake mix with eggs and oil, fold in chocolate chips, and bake a thick, chewy tray of bars in under half an hour. This method gives you the texture of a soft-baked cookie with the ease of a sheet cake, and it scales cleanly for potlucks or after-school snacks.
The genius of this approach is that the dry mix already contains flour, leavening, and sugar balanced for a specific crumb. You’re not guessing ratios—you’re building on a formula that works. The result is forgiving, holds up at room temperature, and welcomes almost any mix-in you have in the pantry. If you enjoyed this, our navigation is worth trying next. Making this cake mix cookie bars at home is surprisingly straightforward once you know the key steps.
Why You’ll Love These Cake Mix Cookie Bars
- Four pantry staples and one bowl—no mixer required, so cleanup stays minimal.
- Thick, chewy bite that stays moist for days thanks to the oil-based batter.
- Endless mix-in options from the same base, so you can repeat without boredom.
- Bakes in a 9×13 pan for 20+ square servings, ideal for crowds or gifting.
Ingredients You’ll Need
- 1 box (15.25 oz) vanilla or chocolate cake mix – the dry base that sets structure and sweetness
- 2 large eggs – bind the batter and add lift so bars aren’t dense
- 1/2 cup vegetable oil – keeps the crumb tender and chewy rather than cakey
- 1 cup semi-sweet chocolate chips – the classic mix-in for pockets of melted chocolate
Ingredient Substitutions
Vegetable oil: Replace with an equal amount (1/2 cup) of melted coconut oil for a faint tropical note. Coconut oil solidifies below 76°F, so the baked bars firm up more at cool room temperature but soften when warmed. Expect a slightly denser bite and a subtle sheen on the surface from the fat swap. The cake mix cookie bars works well for weeknight cooking when time is limited.
Semi-sweet chocolate chips: Use 1 cup of chopped walnuts or pecans instead for a nutty crunch and no melted chocolate pockets. Nuts add protein and fat, which slow browning slightly, so check doneness at the longer end of the bake window. The bars will read less sweet and more toasty from the oven. Storing leftover cake mix cookie bars correctly keeps it tasting good for days.
Vanilla cake mix: Swap to a 15.25 oz red velvet mix for a deeper cocoa color and mild tang from the buttermilk powder. The crumb stays identical in chew but turns rosy; pair it with white chips for contrast. No change to timing or temperature is needed with this direct replacement.
Large eggs: Substitute 2 flax eggs (2 tbsp ground flaxseed plus 6 tbsp water, rested 10 minutes) for an egg-free version. Flax eggs bind loosely, so the bars will be more fragile and cake-like, not as chewy. Bake at the same heat but add 3–4 minutes to set the center fully. For another easy option, check out our kransekake recipe.
Step-by-Step Instructions
- Heat the oven to 180°C / 350°F and line a 9×13 inch pan with parchment so the edges lift out cleanly.
- Empty the dry cake mix into a large bowl, add the 2 eggs and 1/2 cup oil, and stir with a spatula until no white streaks remain and the batter looks like thick brownie dough.
- Fold in the 1 cup chocolate chips until evenly distributed, then scrape the batter into the prepared pan and press it to the corners with a damp spoon.
- Bake on the center rack for 25–30 minutes until the top is matte and a toothpick near the edge comes out with a few moist crumbs but not wet batter.
- Cool in the pan on a rack for 20 minutes before lifting the parchment out and cutting into 24 squares with a sharp knife.
Pro Tips
Rest the mixed batter for 5 minutes before baking so the leavening activates evenly and you avoid tunneling holes in the crumb.
Use a metal pan rather than glass; metal conducts heat faster so the bottom sets before the center overbakes, giving you golden and crispy edges with a soft middle.
For clean cuts, chill the cooled slab for 15 minutes—cold bars fracture less and show neat layers of chip through the crumb, as shown in our party punch spread.
Read technique notes on bar cookie baking if you want the science of pan density and heat spread from a trusted source.
Common Mistakes to Avoid
Do not overmix once the eggs go in; whipping builds gluten and turns chewy bars into a springy cake you didn’t intend. Stop at the streak-free stage.
Never crowd the pan by doubling the recipe in the same 9×13; the center stays gummy at 30 minutes and the edges burn. Bake two batches or use a half-sheet pan with longer time.
Avoid opening the oven early—the temperature drop makes the rising batter collapse, leaving a sunken middle that stays undercooked under the chip layer. You might also like our register.
Serving Suggestions
Cut the slab into 24 squares and plate them on a slate board with a dusting of powdered sugar for a casual dessert table. A scoop of vanilla ice cream on a warm square turns it into a plated treat.
For a drink pairing, the oatmeal cookie smoothie mirrors the flavor profile without more oven time. Pack bars in lunchboxes alongside apple slices for a balanced snack.
Storage and Reheating
Keep cooled cake mix cookie bars in an airtight container at room temperature for up to 3 days, or refrigerate for up to 5 days if your kitchen runs warm. The oil-based crumb stays soft chilled.
Freeze individual squares wrapped in foil for freeze for up to 2 months; thaw at room temperature for 20 minutes. To reheat, warm a bar in a 160°C / 325°F oven for 5 minutes until the chips soften again.
Recipe Variations
Peanut Butter Swirl
Drop 1/3 cup peanut butter by teaspoons over the pressed batter and drag a knife through for ribbons. The added fat makes bars richer and slightly more fragile, so chill before cutting for clean lines.
S’mores Style
Swap chocolate chips for 1/2 cup chips plus 1/2 cup mini marshmallows and 1/2 cup graham cracker chunks. Broil the top for 90 seconds after baking to toast the marshmallows; watch closely so they don’t scorch.
Lemon Poppy
Use lemon cake mix and add 2 tbsp poppy seeds with the chips omitted. The crumb turns bright and faintly crunchy; bake the same time but check the center earlier since seed-loaded batter sets faster.
Spiced Apple
Fold 1 cup finely diced dried apple and 1 tsp cinnamon into a spice cake mix base. The fruit softens in the oven and adds chew; expect a deeper brown top and a harvest-style aroma from the herb brine alternative page.
Cake Mix Cookie Bars
Description
These cake mix cookie bars are a thick, chewy shortcut dessert made from a box of cake mix, eggs, oil, and chocolate chips. They bake in a 9x13 pan in under half an hour with no mixer and minimal cleanup.
Ingredients
Instructions
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Heat oven and line pan
Heat the oven to 180°C / 350°F and line a 9x13 inch pan with parchment so the edges lift out cleanly. This preparation ensures the bars bake evenly and release without sticking after cooling.
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Mix batter
Empty the dry cake mix into a large bowl, add the 2 eggs and 1/2 cup oil, and stir with a spatula until no white streaks remain. The batter should look like thick brownie dough with a uniform color and no dry pockets.
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Fold in chips
Fold in the 1 cup chocolate chips until evenly distributed throughout the dough. Use a gentle hand so the chips are spread consistently and the batter stays thick rather than loosened.
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Press into pan
Scrape the batter into the prepared pan and press it to the corners with a damp spoon for an even layer. The surface should be flat and filled to the edges so the bars bake with uniform thickness.
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Bake bars
Bake on the center rack for 25–30 minutes until the top is matte and a toothpick near the edge comes out with a few moist crumbs but not wet batter. The edges should look set and slightly pulled from the parchment while the center stays soft.
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Cool in pan
Cool in the pan on a rack for 20 minutes before lifting the parchment out and cutting. This rest lets the crumb firm up so the squares hold shape and do not tear when sliced.
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Lift and cut
Lift the parchment out of the pan and cut into 24 squares with a sharp knife. The bars should slice cleanly with visible chocolate chips and a moist but stable interior.
Nutrition Facts
Servings 24
- Amount Per Serving
- Calories 220kcal
- % Daily Value *
- Total Fat 11g17%
- Saturated Fat 3g15%
- Cholesterol 18mg6%
- Sodium 210mg9%
- Total Carbohydrate 29g10%
- Dietary Fiber 1g4%
- Sugars 19g
- Protein 3g6%
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.
Note
- Storage: Keep cooled bars in an airtight container at room temperature for up to 3 days, or refrigerate for up to 5 days if your kitchen runs warm.
- Pro tip: Rest the mixed batter 5 minutes before baking so leavening activates evenly and avoids tunneling, as noted in our chocolate cake recipe.
- Reheating: Warm a bar in a 160°C / 325°F oven for 5 minutes until chips soften; reheat only once.
- Clean cuts: Chill the cooled slab 15 minutes before slicing so the bars fracture less and show neat chip layers.
