Monster cookie bars from cake mix are easy! Use white or yellow cake mix with chocolate chips, peanut butter, oats and more for this boxed cake mix dessert.
Cake mix cookie bars are the bomb. It is a bit of a cheater way to bake “homemade” when guests come over. If you have ever had a cowboy cookie these are kinda’ similar. Meaning you add ALL the add ins you want so there are surprises with every bite. (affiliate links present)
Cake Mix Bar Cookies
The only really big difference between these and cake mix cookies is that you slice them. They are a bit more tender too since you don’t get the crisp outer edges on each one. Especially the center pieces won’t have any of that. Either that is a huge plus to you or if not then you might prefer cookies.
Want to save this post?
Enter your email below and get it sent straight to your inbox.
And be automatically signed up for our free newsletter too!
I guess I would say they are a cross between those and our cake mix brownies. Yes, if you can tell I am all about tweaking a boxed mix into something else entirely. Not to say that we don’t bake it as directed on the back every once and a while, but more than half the time we don’t. 😉
Monster Cookie Bars
Just like kitchen sink cookies you can really add what you love. If you’d prefer Reeses pieces to chocolate pieces then by all means use those. I would stick to our measurements and not omit the oats because that helps with the texture and keeping them together.
- 1 box cake mix 15.25 oz is the right (normal) size
- yellow or white are usually best
- you can try others like red velvet with a white chocolate chips combo
- Brown sugar
- Butter at room temperature is ideal
- Smooth peanut butter
- 1 egg
- 1.5 c quick oats
- Mini chocolate chips or peanut butter chips
- Small candies or chocolates like m&ms are great
- 4 tbsp water
- Large bowl and rubber spatula to mix ingredients
And then a baking sheet is necessary. You can use a piece of parchment paper on the bottom or spray with cooking spray so they don’t stick. I like to only bake one cookie sheet at a time so they all come out with the same consistency.
If you use two racks with one over the other the bottom one will get too done on the bottom for my liking. Just my opinion. Biggest thing is also making sure they’re all the same size. I like using a small cookie scoop. A heaping Tbsp. works well too if you don’t have one of those handy and don’t want to buy one.
Cookie Bars with Cake Mix
This is an easy cake mix recipe that can be altered to your liking. Just tweak the add ins if you use a flavored mix like chocolate cake or something. I think all of these would work well with that but for lemon I might use white chips, no peanut butter but maybe nuts would work better for that instead.
You can jump to recipe below but this is a quick rundown of how we made this cake mix cookie bar recipe over the weekend. Get out a 9×12 baking pan and let’s get started;
- Start off by preheating the oven to 350 degrees F.
- In a large mixing bowl, combine cake mix, water, egg, butter and peanut butter. Add oats and brown sugar, mix well.
- Gently fold in chocolate chips and M&Ms.
- Spread the dough into a prepared pan. (I used parchment paper for easier removal.) **If you would like thicker bars, you can use a smaller 9×9 baking dish as well.
- Bake for about 25-30 minutes cook time, or until golden brown.
- Remove from the oven and let cool completely in the pan, before slicing.
It is important to not bake this too long or it will dry out. I would rather have it a bit underdone than over.
How do you know when a cookie bar is done
This is KEY when you are baking this or a pan full of homemade brownies. The texture is everything!! Set for the minimum bake time listed and then turn on the light. What you want is the outside edges to start cracking and firming up and the middle to be tender but not wet. If it looks like it is close use a toothpick.
Insert into the center and if it is still wet and liquidy, give it 5 more minutes and check again. However when you pull it out if it is clean but with very moist crumbs attached, pull it out. Do NOT slice it yet though. Set it on a cooling rack until it is at room temperature. That gives it time to continue baking in the pan. Then it is will be perfect!!
Chocolate Chip Cookie Bars
You can go really simple too if you wanted to. With just chips and maybe some crushed walnuts you’ll love these just the same. Use what is in your cupboards y’all. That is what I do when I am in a real pinch. If you do have all the things though you should really go for it. even some crushed pretzels will give it a sweet savory combo.
M&M Cookie Bars
Want to see a few of my favorite things that I am totally obsessed with?? Take a peek and see how many you might already have…twinsies!
Cookie Bars From Cake Mix
- 1 9×13 pan or 9×12
- Preheat the oven to 350 degrees F. In a large mixing bowl, combine cake mix, water, egg, butter and peanut butter. Add oats and brown sugar, mix well. Gently fold in chocolate chips and M&Ms.
- Spread the dough into a prepared 9×12 baking pan. (I used parchment paper for easier removal.) **If you would like thicker bars, you can use a smaller 9×9 baking dish as well.
- Bake for approximately 25-30 minutes, or until golden brown. Remove from the oven and let cool completely in the pan, before slicing.