Cake Mix Cookie Bars Recipe

These cake mix cookie bars are one of those recipes you’ll turn to whenever you need a quick, crowd-pleasing dessert. With just four ingredients and minimal prep time, they’re perfect for those days when you’re craving something sweet but don’t have the energy (or ingredients!) for a full-blown baking project. The best part? You don’t need any fancy skills—just mix, bake, and enjoy. The soft, chewy texture and pops of chocolatey M&Ms make these bars irresistible.

this RECIPE

A sweet family favorite with a twist 🍪

I remember the first time I made these cookie bars—it was one of those lazy Sunday afternoons when I wanted something homemade but wasn’t in the mood for anything complicated. I spotted a box of cake mix in the pantry and figured, “Why not?” I tossed in some M&Ms for extra color and crunch, and within minutes, the whole house smelled like a bakery. By the time they were out of the oven, my family was already circling the kitchen, asking, “Are they ready yet?” These bars have since become a staple in our home, especially for last-minute get-togethers and school events.

The history of cake mix bars

Cake mix cookies and bars have been around since the 1940s, shortly after boxed cake mix was introduced to home bakers. Originally, cake mix was a way to make cakes quickly, but soon, creative bakers realized it could be used for more than just cakes. Over time, cake mix evolved into a shortcut ingredient for all sorts of desserts, including cookies, bars, and even crumbles. Nowadays, there’s a cake mix variation for nearly every flavor and occasion. This particular recipe uses yellow cake mix, which provides a soft, buttery base that’s perfect for cookie bars.

Let’s talk ingredients: simple but oh-so-good

Here’s a quick rundown of the main ingredients and why they work so well together:

• Yellow cake mix: This forms the base of the bars, giving them a soft, cake-like texture that’s still dense enough to hold together as a bar. If you’re out of yellow cake mix, you could substitute with white cake mix, though the flavor will be a bit milder.
• Butter: Adds richness and helps create that soft, chewy texture. I like to use unsalted butter, but if you’re using salted, just be mindful that it will add a hint of saltiness to the bars. Melted butter works best for easy mixing.
• Eggs: These add structure to the bars and help bind everything together. If you’re out of eggs, you could try a flaxseed egg substitute, though the texture will be slightly different.
• M&Ms: These colorful chocolate candies add both crunch and sweetness. You can use classic milk chocolate M&Ms, or switch it up with peanut, peanut butter, or even seasonal flavors for a fun twist.

Kitchen gear: what you need (and what you can totally skip)

For this recipe, you don’t need much more than the basics, which is part of the appeal!

• 9×9 baking pan: A square pan is ideal for these bars, as it gives them the perfect thickness. If you don’t have a 9×9 pan, an 8×8 pan will work, but the bars will be a bit thicker and may need a few extra minutes of baking time.
• Mixing bowl: A medium-sized bowl is perfect for mixing the ingredients. Since there’s no electric mixer required, just grab a sturdy spoon or spatula.
• Parchment paper: This makes removing the bars from the pan a breeze. If you don’t have parchment, you can grease the pan generously, but parchment paper makes it so much easier to lift out the whole batch in one go.

Step-by-step: making your cookie bars

Ready to bake? Let’s walk through the steps together!

1. Preheat the oven: Start by preheating your oven to 350°F (175°C). This ensures the bars bake evenly. Grease a 9×9 baking pan and line it with parchment paper, letting the edges hang over the sides. This will make it easier to lift the bars out later.
2. Mix the ingredients: In a medium bowl, combine the yellow cake mix, melted butter, and eggs. Stir until the mixture is smooth and everything is well combined. It will be thick and slightly sticky—that’s exactly what we’re going for.
3. Add the M&Ms: Fold in the M&Ms gently so they’re evenly distributed. I like to save a handful to sprinkle on top for extra color, but that’s optional.
4. Spread the batter: Transfer the batter into your prepared pan, using a spatula to spread it out evenly. It’ll be thick, so take your time to press it into the corners. Don’t worry if it looks a bit uneven; it’ll even out as it bakes.
5. Bake: Pop the pan in the oven and bake for 25-30 minutes, or until the bars are golden brown and a toothpick inserted in the center comes out clean. The edges should be slightly crisp, while the center remains soft and chewy.
6. Cool and cut: Once baked, let the bars cool in the pan for about 10 minutes. Then, using the parchment paper, lift the entire slab out of the pan and transfer it to a cutting board. Slice into nine squares (or more if you prefer smaller pieces).

Variations to try if you’re feeling adventurous

Looking to switch things up? Here are a few fun variations you can try:

• Chocolate lovers’ twist: Use a chocolate cake mix instead of yellow for a richer, more decadent treat. You can also swap the M&Ms for chocolate chips or chunks for a double-chocolate version.
• Peanut butter swirl: Add a few dollops of peanut butter on top of the batter before baking, then swirl it in with a knife. This adds a delicious peanut butter flavor that pairs perfectly with the M&Ms.
• Nutty addition: Stir in a handful of chopped nuts (like walnuts or pecans) for added crunch. This works especially well if you’re using peanut M&Ms!

Serving and presentation ideas

For serving, I like to arrange these bars on a platter lined with a paper doily or parchment for a little extra flair. If you’re serving them at a party, cut them into smaller squares to make them easy to grab. You can also sprinkle a bit of powdered sugar over the top for a pretty finishing touch. These bars are perfect as-is, but they’re also delicious slightly warm with a scoop of vanilla ice cream on the side.

Perfect drink pairings

These cake mix cookie bars go wonderfully with a variety of drinks. Here are a few ideas:

• Milk: A classic choice! The creamy, cold milk balances the sweetness of the bars.
• Hot chocolate: For a cozy pairing, serve these bars with a warm mug of hot chocolate. Add a dollop of whipped cream for extra indulgence.
• Coffee or espresso: If you’re serving these as an afternoon treat, a hot cup of coffee or espresso complements the sweetness without overpowering it.
• Iced tea: For a lighter option, try pairing with unsweetened iced tea. The mild bitterness of the tea contrasts nicely with the bars’ sweetness.

Storage and reheating tips

Store these cookie bars in an airtight container at room temperature for up to 3 days. They actually get softer as they sit, which makes them even more delicious! If you’d like to keep them for longer, you can refrigerate them for up to a week. Just let them come to room temperature before serving for the best texture. For a warm treat, pop a bar in the microwave for about 10 seconds.

Scaling the recipe for a crowd

If you’re baking for a larger group, you can easily double the recipe and bake it in a 9×13-inch pan. The bars will still bake up beautifully, though they may need a few extra minutes in the oven. Keep an eye on them, and use the toothpick test to check for doneness. I’ve found that doubling the recipe still gives the same chewy, delicious texture—just with more to share!

Common questions about cake mix cookie bars

1. Can I use a different flavor of cake mix?
Yes! Chocolate, white, or even funfetti cake mix works great in this recipe. Each will give a slightly different flavor but will still be delicious.

2. Can I add extra mix-ins?
Absolutely. Try adding chocolate chips, nuts, or shredded coconut. Just be careful not to overload the batter, or it may not hold together as well.

3. Can I make these gluten-free?
Yes, you can use a gluten-free cake mix to make these bars gluten-free. The texture may be slightly different, but they’ll still be tasty.

4. Do I need to chill the dough?
Nope! There’s no need to chill the dough for this recipe, which is why it’s so quick and easy.

5. Can I freeze these bars?
Yes, these freeze well. Wrap individual bars in plastic wrap, place them in an airtight container, and freeze for up to 3 months. Thaw at room temperature when you’re ready to enjoy.

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