These Halloween cookie bars are soft and gooey with a crunchy golden crust studded with ghoulish M&Ms!
These yummy cookie bars are adapted from my Red, White, and Blue M&M Cookie Bars recipe. They were such a hit during Memorial Day, 4th of July, and Labor Day, so I decided to make them for Halloween, too! This time, I used the Halloween Ghoul Mix M&M's with an assortment of orange, purple, and lime green chocolate candies. I also added big and small candy eyeballs, which made them look adorably monster-like! However, googly eyes are optional if you cannot find them.
Why We Love this Recipe
I love making holiday treats like these! Halloween cookies are so much fun because you get to make them as creepy or cute as you like! Here are a few more reasons why we love these:
- It takes only 10 minutes and one large bowl to make the dough!
- These are perfect for sharing! One batch will produce several bars, so they are ideal when you are planning to bring them at school, in the office, or at any Halloween parties you are going to!
- The bars are so chewy and moist with a crackly top and generously dotted with M&Ms- a cookie and a chocolate lover's dream come true!
- They are easy to make, customizable, and can be made with more spooky mix-ins to up your Halloween game!
Leftover Halloween Candy Cookie Bars
This recipe is super versatile! Instead of M&M's, use up leftover Halloween candy bars. Try mixing in candy corn, Reese's peanut butter cups, Kit Kats, Snickers, Hershey's Bars, chocolate chips, nuts, and whatever goodies your kids were able to get trick or treating.
Ingredients
If you are an avid baker like me, you will probably have most of the ingredients in your pantry. Just grab the Halloween-inspired goodies at the nearest supermarket, and you're all set!
Here's what you need:
- Halloween M&M's -- If you cannot find these, feel free to use regular M&M's. I'd probably use their orange, green, and brown ones to keep the theme going.
- All-purpose flour
- Unsalted butter -- Use at room temperature. This will give the cookie bars a richer taste and make them moist.
- Granulated and Brown sugar -- Aside from giving the cookie dough its sweetness, these also produce a nice golden color.
- Vanilla extract -- Enhances the flavor of the cookie dough.
- Eggs -- Binds the ingredients together and are responsible for the chewy texture.
- Baking powder and baking soda -- The leavening agents used to make the dough rise and keep them soft.
- Salt
- Candy eyeballs -- Use big and small ones. These are optional but will make the bars look fun and cute!
Equipment Needed
You need the following equipment to make these Halloween M&M Cookie Bars.
- Rimmed baking sheet -- I used a large rimmed baking sheet about 12x17, which is ideal. You can also use a 9x13-inch baking dish for thicker cookies because it has higher edges, so the dough won't spill. You will need to bake it longer, for about 25 to 30 minutes.
- Hand mixer or stand mixer -- I typically use my KitchenAid stand mixer, but feel free to use a hand mixer or your elbow grease!
- Large mixing bowl
- Rubber spatula
How to Make Halloween M&M Cookie Bars
This one-bowl holiday cookie bar recipe is so simple and straightforward to make that it'll be your go-to whenever you need something quick and delicious. Simply swap the M&M colors to fit any special occasion.
Preparations:
- Preheat the oven to 350°F.
- Grease a large rimmed baking sheet with nonstick spray
Steps:
- Cream the butter. Whip the butter and sugars in a large mixing bowl for about a minute or until the mixture is light and fluffy.
- Add the rest of the ingredients. Beat in the vanilla and eggs. Then, stir in the flour, baking powder, baking soda, and salt until everything is just mixed. Fold in the M&M's.
- Assemble. Spread dough evenly into the prepared baking sheet using a large rubber spatula. Sprinkle an additional ½ cup of M&M's over the top and lightly press them into the dough.
- Bake! Bake for about 20 to 25 minutes, depending on your desired level of doneness. It should be good once the edges are golden.
- Cool and serve. Let cool completely before cutting into squares with a plastic knife and serving.
Tips to Remember!
- I use Baker's Joy instead of lining the pan with foil or parchment. If you do not have this, you can use any nonstick spray or line your baking pan with parchment paper instead.
- Do not use a jelly roll size pan. That size is too small, and the dough will ooze out during baking because of the short edges.
- The dough may spread thin if you are using a large sheet pan, but it will puff and close holes during baking.
- If you are using candy eyeballs, add them after baking because they will melt in the oven.
- If you like the cookie bars to turn out crispier, use more granulated sugar and less brown sugar.
- I like my cookie bars chewy and super moist, so I take them out of the oven when they are lightly golden on top. However, if you prefer them less doughy, bake longer until they are a darker golden exterior.
Frequently Asked Questions
Why are my cookie bars soft and mushy?
It is normal for the cookies to be super gooey straight off the oven. You must be patient and let them cool to firm up before serving.
How do I know if the cookie bars are done?
A good way to test if the pan of cookies is done is the look of the top. They are done with golden and crackly. The toothpick test doesn't work great for these because you will almost always have gooey cookie or melted chocolate on the toothpick.
How to cut cookie bars cleanly?
The best way to cut cookie squares from a sheet pan is with a plastic knife. Wipe it clean as necessary. This also prevents scratching the baking sheet.
Storage and Leftovers
The best way to store cookie bars is in a sealed container at room temperature for a few days. If you want them to last longer, refrigerate them for 2 weeks, or keep them frozen for months.
More Recipes for Halloween
- Pumpkin Spice Cut Out Cookies
- Monster Sugar Cookies
- Monster Cupcakes
- Snack o' Lantern Fruit Cups
- Spider Oreo Cookies
Eat It, Rate It, Share It!
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Recipe Card
Halloween Cookie Bars with M&M's
Ingredients
- 1 cup unsalted butter , room temperature
- 1 ½ cups light brown sugar
- ½ cup granulated sugar
- 2 teaspoons vanilla extract
- 3 large eggs
- 3 cups all-purpose flour
- 1 teaspoon baking powder
- 1 teaspoon baking soda
- 1 teaspoon salt
- 2 ½ cups Halloween M&M's
- Candy eyeballs , big and small (optional)
Instructions
- Preheat oven to 350°F. Grease large rimmed baking sheet with nonstick spray. (I use Baker’s Joy, but any brand can be used.)
- In a large mixing bowl, cream together the butter and sugars until light and fluffy (about 1 minute). Beat in the vanilla and eggs. Stir in the flour, baking powder, baking soda and salt. Fold in 2 cups of the M&M's.
- Using a large rubber spatula, spread dough evenly into baking sheet. The dough may be thin if using a large sheet pan, but will puff and close holes during baking. Sprinkle additional ½ cup of M&M's over top and lightly press into the dough.
- Bake for 20 to 25 minutes, until baked to desired doneness and edges are golden. Do not over bake. Let cool completely before serving.
- To serve, cut into squares with a plastic knife.
Notes
- I use Baker's Joy instead of lining the pan with foil or parchment. If you do not have this, you can use any nonstick spray or line your baking pan with parchment paper instead.
- Do not use a jelly roll size pan. That size is too small, and the dough will ooze out during baking because of the short edges.
- The dough may spread thin if you are using a large sheet pan, but it will puff and close holes during baking.
- If you are using candy eyeballs, add them after baking because they will melt in the oven.
- If you like the cookie bars to turn out crispier, use more granulated sugar and less brown sugar.
- I like my cookie bars chewy and super moist, so I take them out of the oven when they are lightly golden on top. However, if you prefer them less doughy, bake longer until they are a darker golden exterior.
- Store in airtight container at room temperature for up to 5 days. Or refrigerate for 2 weeks, or freeze for months.
- Nutrition information is an estimate only.