Monster Cookie Bars

These monster cookie bars are everything you could possibly want! They're thick, soft, and loaded with 3 types of M&Ms. The combination of chewy oats, creamy peanut butter, and chocolate come together to make the BEST cookie bars you will ever try! 

Why you'll love it

These cookies are a classic just like my brown butter chocolate chip cookies and my sugar cookie bars. If you are a fan of monster cookies, you will absolutely love how quick and easy it is to make and share them in bar form. There is no need for any special secrete ingredients to make these the best dessert bars every. They are perfectly soft and chewy with no added ingredients beyond what you will already have available. if you want to know what really makes this THE recipe you need to try, it's because:

• They're quick and easy. Simply mix and bake; no chilling required! 
• The center is soft and chewy, while the the outside is buttery and crisp
• It has the perfect balance of peanut butter, chocolate, and oats
• You can customize it so it is exactly how you like it! Add or omit whatever you want

If you want more delicious cookie goodness, be sure to check out my cookbook, Cookie School where I share all the tips and tricks to making the best cookies ever. 

Key ingredients

The ingredient list for these bars is very simple and uses only pantry staples. These are some of the key ingredients and any potential substitutions you may use, if needed! You can find the full list of ingredients and measurements in the recipe card below. 

• Peanut butter - The most important ingredient is the peanut butter. I recommend using a good quality creamy peanut butter. My favorite brand to use is Jif. I do not recommend natural peanut butter. you can use alternatives like creamy almond butter as long as the brand you are using doesn't have a lot of separation that occurs in the jar. 
• Oats - Old-fashioned oats or rolled oats are the type I typically prefer and recommend because it gives a chewier texture and fun mouthfeel. You can use quick oats if you are looking for bars that don't have a very oaty texture. If you only have old fashioned oats, but want the smoothness of quick oats, use a food processor to break the oats down into smaller pieces. 
• Chocolate and M&Ms - This is where you can get really creative! You can experiment with any kind of chocolate chips or chopped chocolate you like. you can also add in some peanut butter chips to add more peanut butter flavor. Experimenting with M&Ms is also a great way to change things up. I used a bag of a peanut butter mix M&Ms that had some that were peanut butter filled and others with peanuts in them. You can also change up the m&m colors for special occasions. This is also a great opportunity to use up leftover Halloween candy. Reese's pieces also make a delicious addition. 

How to make

These bar cookies are made just like all your favorite drop cookies, but here we will go more into some tips and tricks to get them absolutely perfect. 

1. Grab all your ingredients and measure them out. Make you use room temperature ingredients. Line your baking pan with parchment paper.
2. Add your butter, sugars, peanut butter, and vanilla in the large bowl of a stand mixer. Whip using a paddle attachment until everything is light in color and super fluffy.
3. Beat in the egg and yolk until it is fully incorporated and the mixture looks light and fluffy again.
4. Mix the dry ingredients together in a separate bowl. This helps ensure that all the dry ingredients get more evenly dispersed in the dough before you add it to the wet ingredients.
5. Slowly add in the dry ingredients and mix just until there are no streaks of flour. Fold in the chocolate chips and m&ms. 
6. Spread the monster cookie dough into your baking pan into an even layer. 
7. Bake until the edges are golden brown. The center may not be as golden, and perhaps a little puffy. That is fine. Remove from the oven and allow to cool slightly before slicing into bars. 

Amanda's expert baking tips

• The most important way to ensure you get the best results is to make sure you are correctly measuring your ingredients, particularly the all-purpose flour. You should fluff up the flour and then spoon it into your measuring cup then sweep of the excess. If you want to make sure you get consistent results, you can convert the recipe to metric and use a kitchen scale.
• It is important to use all room temperature ingredients because it helps everything to incorporate well together. You can quickly bring your eggs to room temperature by leaving them in very warm water for five minutes before cracking them. 
• Don't skip the extra yolk. It helps with adding more richness and enhances the texture of the dough. 
• When beating the butter, sugars, peanut butter, egg, and vanilla, make sure to whip it on medium-high for a few minutes until the mixture is light and fluffy. This helps the sugar crystals to dissolve and give you a smooth dough and chewy bars.
• Always scrape the sides and bottom of the bowl so that everything gets well-combined. 
• Don't overmix the dough when adding in the dry ingredients! You want to mix just until there are no streaks of flour. Mixing too much can develop the gluten in the all-purpose flour which will leave you with dry, tough cookies. I recommend doing this part by hand with a spatula.
• If you really want to enhance the flavors and let them develop more, you can cover your bowl with plastic wrap and allow it to chill in the refrigerator for up to three days. You will need to let the dough warm for at least 30 minutes before attempting to spread it onto your baking pan to bake. 
• Let the cookies cool for about 5 minutes before cutting to ensure you get perfect, even cuts. 

Storage info

The best way to store your chewy monster cookie bars is to keep then in an airtight container. Keeping a layer of parchment paper helps keep your bars easy to take out when needed. 

FAQs

Recipe Card