Christmas M&M Oatmeal Bars

Chewy oatmeal cookie bars come together in a few steps and are so easy to bake! They are loaded with Christmas M&Ms. No chill time required!

When you feel like having cookies but don't want to roll them out, make these bars!

With only a handful of simple ingredients, these bars are so easy! It all gets mixed in one bowl, no electric mixer required.

I made a regular version of these Christmas M&M Cookie Bars and decided we need an oatmeal version! These are thick bars full of hearty oats. They are perfect for a cookie exchange or holiday party!

For more cookie bars, try Chocolate Peanut Butter Stuffed Cookie Bars, Soft and Chewy Gingerbread Cookie Bars, and Cookie Butter Chocolate Chunk Bars. 

Why this recipe works

• Easy to make.- Only simple ingredients that are probably already in your pantry!
• Festive - The holiday M&M's add a great Christmas touch!
• Soft & chewy - These bars are super gooey and delicious!
• No electric mixer - This recipe is so easy you don't even need an electric mixer, just a whisk and spatula.

Ingredients Notes

Full recipe and ingredients are in the recipe card below. Feel free to scroll through this section to view certain key ingredients we’re using!

All-purpose flour – This flour is used for the bars and cannot be substituted for any other.

Butter – Unsalted. This will be melted and cooled.

Brown sugar – I used dark brown sugar but light brown sugar works as well!

Eggs – Must be at room temperature before starting your bake.

Oats - Make sure you use rolled oats, also known as large flake oats. Quick oats will not work.

M&M's - I used Christmas M&M's for this recipe. Feel free to use any seasonal or regular ones!

Step by step instructions

Here is how to make and bake this Christmas Oatmeal M&M Cookie Bars. You will need a 9×9 baking pan lined with parchment paper, 2 mixing bowls, a whisk, and a spatula.

Step 1 – Prep. Grease the pan. For easy removal of the cookie bars, place parchment paper on the bottom and 2 sides of the pan. Gently grease the other two sides and then set aside.

Step 2 – Mix dry ingredients. In a medium sized bowl, add in flour, oats, cinnamon, baking soda, baking powder, and salt. Stir to combine and set aside.

Step 3 – Whisk wet ingredients. In a large bowl, whisk butter and brown sugar. Then whisk in eggs, one at a time, and the vanilla extract.

Step 4 – Add in dry ingredients. Toss in the dry ingredients. Mix until no dry streaks appear. Don't over-mix. As soon as the flour disappears, stop mixing.

Step 5 – Add M&M's. Add in Christmas M&M's and mix in a few more times.

Step 6 – Transfer and bake. Place the batter into the prepared pan and spread evenly. Add with a sprinkle of extra M&M's if desired. Bake for 25-30 minutes or until the top is a light golden brown and a toothpick inserted comes out clean. Mine took 28 minutes exactly.

Let the cookie bars cool down completely, slice, and enjoy!

Expert Baking Tips

Here are a few baking tips from my kitchen to yours!

• Use a gram scale. I cannot emphasize this enough! It is the most accurate way of measuring your ingredients in the kitchen. This is one of my favourites.
• Use rolled oats. Quick oats are smaller and don't cook the same!

FAQ

Can I bake these in a different pan?

Yes, you can bake them in an 8x8 pan but they will be thicker and bake longer.

Can I brown the butter?

Yes, if you want to elevate these cookie bars and take them to the next level, brown the butter.

Why don't you chill the cookie dough?

This cookie dough is placed and baked in a pan, so it doesn't have any space to spread like it would if it was scooped into cookies on a cookie sheet. So there's no need to chill the dough!

Can I scoop these into cookies?

I haven't tried using this dough in cookie form so I can't say. If you want to make cookies, try baking Christmas M&M Oatmeal Cookies.

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