Halloween M&M Cake Mix Cookie Bars

If you’re looking for a quick and festive Halloween treat that delivers big flavor with almost no effort, these Halloween M&M Cake Mix Cookie Bars are the perfect pick! They start with a simple box of chocolate cake mix and bake into soft, chewy cookie bars loaded with melty chocolate chips and bright Halloween colored M&M’s. Every slice is packed with chocolate and pops of spooky color, making them ideal for classroom parties, trick‑or‑treat night, bake sales, or any Fall celebration!

Easy Halloween Cookie Bars with Cake Mix!

If you need a quick and festive Halloween treat that everyone will love, these Halloween M&M Cake Mix Cookie Bars are the answer! They’re soft, chewy, loaded with chocolate, and packed with bright Halloween colored M&M’s that make every slice look party ready. Best of all, they start with a box of cake mix – which means minimal measuring, no fuss, and a dessert that comes together in minutes!

These cookie bars are perfect for classroom parties, trick‑or‑treat night, bake sales, or any time you want a fun Halloween dessert without spending hours in the kitchen. They’re the kind of treat that disappears fast and gets requested every year!

Why this Recipe Works:

• Cake Mix Keeps Things Simple – Starting with a boxed chocolate cake mix means no measuring flour, sugar, or cocoa. It gives you consistent results and cuts prep time way down.
• Chewy, Soft Cookie Bar Texture – The combination of oil and eggs transforms the cake mix into a thick cookie dough that bakes into soft, chewy bars instead of fluffy cake.
• Perfect for Parties and Gifting – These bars slice beautifully, travel well, and look instantly seasonal without any decorating – ideal for classroom parties, bake sales, or trick or treat night.

Ingredients You’ll Need:

• 1 box Chocolate Cake Mix – Provides the structure, chocolate flavor, and makes these cookie bars super quick and easy.
• 1 tbsp Flour – Adds a little extra stability so the bars bake up thicker and hold their shape when sliced.
• 2 Eggs – Binds the batter and helps create that chewy, cookie bar texture.
• 1/3 cup Oil – Keeps the bars soft, moist, and tender – classic for cake mix cookies.
• 1 cup Chocolate Chips – Adds pockets of melty chocolate throughout the bars for extra richness.
• Halloween M&M’s – Brings the festive color, crunch, and fun Halloween vibe to every bite.

How to Make Halloween M&M Cake Mix Cookie Bars

1. Preheat oven to 350 degrees. Spray 9 x 13 pan with non-stick spray and set aside.
2. Add 1 box of chocolate cake mix to a bowl with 1 tbsp flour. Mix well.
3. Add 2 eggs and 1/3 cup oil to the mixture. Beat until well combined.
4. Stir in 1 cup chocolate chips.
5. Bake for 20 minutes. Press M&M’s into the top of the bars right after removing from the oven.

More Halloween Cookies:

• Monster Eye Cookies
• Halloween M&M Cookie Bars
• Peanut Butter Spider Cookies
• Halloween M&M Cookies
• Halloween Cookie Pizza