If you’re wondering what to do with leftover Halloween candy, I’ve got the answer! These leftover Halloween candy cookie bars are the perfect way to use up leftover Halloween candy before it gets stale. 

You don’t have to wait until after the holiday to make these Halloween candy cookie bars! Bake them up to serve alongside a sweet Halloween spread that includes Halloween Spider Cookies, Halloween Oreo Balls, Halloween Dirt Cups, and Ghost Cupcakes.

Leftover Halloween Candy Cookie Bars topped with colorful M&M's, chopped snickers, Kit Kat, milk duds, Reese's and more!

Why This Recipe Works

  • Leftover Halloween candy recipe. Listen, Halloween candy is great. But sometimes you just need something new. That’s where these Halloween cookie bars come in. These loaded cookie bars use up leftover Halloween candy in a fun and delicious way.
  • Easy Halloween dessert bars. These delicious cookie bars are rich, yummy, and festive! Perfect for using up candy after Halloween, or for bringing to a Halloween party. Plus, I love making cookie bars because they’re simpler than making individual cookies. You just squish all the dough in a pan!

Ingredient Notes

  • Butter: Melted and slightly cooled. Using melted butter helps create a chewier, more brownie or bar-like texture, rather than a regular cookie texture.
  • Baking soda: This is the leavening agent that will give a little bit of rise to the bars.
  • Brown sugar: I usually use light brown sugar, but you can use dark, too. Adding brown sugar to the cookie dough helps create a denser texture due to the liquid (molasses) in the sugar.
  • Granulated sugar: White or granulated sugar does the opposite of brown sugar, in that it helps create a crisper texture. Adding white sugar in addition to brown sugar will keep these cookie bars from being TOO dense.
  • Eggs: Eggs are a binding and rising agent in baking. This recipe calls for one whole egg plus one whole yolk to give these bars a thicker and softer texture.
  • Leftover Halloween candy: This is where the fun begins! You can use any kind of candy you like, but I recommend sticking to chocolate-based candies and avoiding any gummy or fruity candies.
  • Semi-sweet chocolate chips: More chocolate is never a bad thing in my book, so in addition to chocolate candies, we’re adding chocolate chips! Using semi-sweet chocolate chips will help provide a counter to the milk chocolate commonly used in Halloween candies.
Leftover Halloween Candy Cookie Bar recipe ingredients portioned into glass bowls on a light gold colored baking sheet: flour, eggs, butter, vanilla, sugar, chocolate chips, and a variety of candy.

Step-by-Step Instructions

  1. Chop Halloween candy. Chop various chocolate candies into bite-size pieces. You need 3 cups total. Set aside 1 cup of candy pieces, and place the other 2 cups of chopped candy in the freezer to chill for at least 15 minutes.
  2. Prep oven and pan. Preheat your oven to 325°F. Line a 9×13-inch pan with foil or parchment paper. Leave some hanging over the edges so the bars are easy to remove from the pan. Spray with nonstick cooking spray. 
  3. Mix wet ingredients. Melt 12 tablespoons of unsalted butter in a microwave-safe bowl. Add the melted butter to a large mixing bowl, along with ½ cup of granulated sugar and 1 cup of brown sugar. Whisk butter and sugar until well combined, then add 1 egg, 1 egg yolk, and 2 teaspoons of vanilla and whisk until combined. 
  4. Combine dry and wet ingredients. In a medium bowl, whisk together 2 cups plus 2 tablespoons of all-purpose flour, ½ teaspoon of salt, and ½ teaspoon of baking soda. Add the dry ingredients to the wet ingredients and give it a few stirs with a rubber spatula.
  5. Add leftover Halloween candy and chocolate chips. To the dough, add 1 cup of semi-sweet chocolate chips and 1 cup of Halloween candy that’s been chopped into bite-size pieces. Fold chocolate and candy into the dough until combined.
Four images, each using a glass bowl showing the beginning process of how to make Leftover Halloween Candy Cookie Bar dough; melted butter with sugar and eggs added, then dry ingredients and then candy mix-ins.
  1. Press into pan and add more candy. Press the dough into the prepared 9×13-inch baking pan. Remove chopped candy from the freezer and scatter it over the top of the bars. If needed, press the candy down gently into the dough to make it stick. If desired, sprinkle flaky sea salt over the top of the bars. 
  2. Bake. Bake Halloween cookie bars for 25-30 minutes. Edges of the cookie bars should be slightly golden brown, firm to the touch, and slightly pulling away from the edge of the pan.
  3. Let cool. Remove baking pan from the oven and let the bars cool on a wire rack until they reach room temperature. Once the bars have reached room temperature, use the overhanging foil or parchment paper to remove them from the pan. Place on a cutting board and cut into bars. Enjoy!
Top left photo: Leftover Halloween Candy Cookie Bar dough in a glass bowl, top right: dough is flattened into a rectangle pan, bottom left: leftover Halloween candy overtop of the cookie bar dough; bottom right: baked and cut cookie bars with chopped candy overtop.

Recipe Tips

You can use any candy you like, but I advise only using chocolate candy, not gummy candy or fruit or sour candy. The only exception would maybe be candy corn. If you like candy corn, I think it could be yummy in these cookie bars! I used Reese’s peanut butter cups, Kit Kats, Snickers, M&M’s, and Whoppers. 

To make the candy easier to work with, chill it in the freezer for 15 minutes. 

You can use a different flavor of chocolate chips if you like! White chocolate chips, milk chocolate chips, and even butterscotch chips would be delicious. You can also experiment by subbing the chocolate chips with another cup of chopped candy. 

For soft and tender cookie bars, make sure to not overbake.

Make Ahead, Storing, and Freezing

Make Ahead: You can make the cookie dough up to a day in advance and chill it in the fridge until ready to bake. Follow baking instructions like normal. Cookie bars are good for several days, so you can also make these a couple of days in advance if you want to bring them to an event or snack on them through the week. 

Storing: Store Halloween cookie bars in an airtight container at room temperature for 3-4 days or in the fridge for 5-6 days.

Freezing: To freeze the cookie bars, either freeze them in the pan, not cut into squares, or freeze the squares individually. If freezing the baked cookie bars in the pan, double wrap the pan in plastic wrap and freeze. If freezing for longer than 1 week, add an extra layer of aluminum foil. To freeze individual cookie bar squares, wrap each square in plastic wrap twice and store them in an airtight container or Ziplock bag in the freezer for 1-2 months. Halloween candy cookie bars should last in the freezer for 1-2 months.

A hand holding a square piece of Leftover Halloween Candy Cookie Bars topped with M&M's, milk duds, and other leftover Halloween candy pieces.

Recipe FAQs

What kind of candy is best for cookie bars?

Baking with leftover Halloween candy is a great way to use up leftover candy. However, not all candy works well. I recommend sticking to chocolate candies. Avoid gummy, sour, or fruity candies.

Can you freeze cookie bars?

Yes, cookie bars can be frozen. You can freeze these cookie bars in the pan, unsliced, or freeze individual slices wrapped in plastic wrap.

Can I use this recipe to make cookies instead?

No. The ratios for cookies instead of cookie bars are very different. Melted butter instead of softened butter, more brown sugar, and an extra egg yolk make these more dense and chewy, not great for cookies.

Four squares of Halloween cookie bars resting on their sides, stacked against each other.

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Leftover Halloween Candy Cookie Bars topped with colorful M&M's, chopped snickers, Kit Kat, milk duds, Reese's and more!
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5 from 1 vote

Leftover Halloween Candy Cookie Bars

Use the leftover Halloween candy to make these delicious cookie bars!
Prep Time: 20 minutes
Cook Time: 25 minutes
Total Time: 45 minutes
Servings: 20 servings

Ingredients
 

  • 12 tablespoons unsalted butter - melted
  • 1/2 teaspoon salt
  • 1/2 teaspoon baking soda
  • 1/2 cup granulated sugar
  • 1 cup light brown sugar - packed
  • 1 large egg
  • 1 egg yolk
  • 2 teaspoons vanilla extract
  • 2 cups + 2 tablespoons all-purpose flour
  • 1 cup semi-sweet chocolate chips
  • 1 cup leftover Halloween candy - chopped into bite size pieces (M&M's, Kit Kats, Snickers, Milky Way, 3 Musketeers, Milk Duds, Whoppers etc)

For Topping

  • 2 cups leftover Halloween candy - chopped into bite size pieces and chilled in the freezer for 15 minutes or until firm
  • Maldon sea salt - for sprinkling overtop

Instructions
 

  • Preheat oven to 325°F. Adjust oven rack to middle lower position. Line a 13×9 inch pan with foil or parchment paper, letting some excess hang over the sides to make the bars easier to remove. Spray with nonstick cooking spray.
  • In a large bowl whisk the butter, brown sugar and granulated sugar until well combined. Mix in the egg, egg yolk, and vanilla. 
  • In a medium bowl whisk the flour, salt, and baking soda. 
  • Using a rubber spatula, mix the dry ingredients in. After a few stirs, (there should be lots of flour still visible), add the chocolate chips and 1 cup of chopped candy pieces. Fold until combined.
  • Press the batter into the prepared pan. Remove the chilled chopped candy from the freezer and scatter it atop the bars, press down lightly if needed so that the candy will stick into the bars. Sprinkle flaky sea salt over top. 
  • Bake for 25-30 minutes or until the bars are lightly golden brown on the edges, slightly firm to the touch, and the edges are slightly pulling away from the sides of the pan.
  • Remove from the oven and let cool on a wire rack until room temperature. Remove the bars using the overhanging parchment or foil. Transfer to a cutting board and cut into squares. 

Notes

Store leftover cookie bars in an airtight container at room temperature for 3-4 days, or in the fridge for 5-6 days. 
I recommend only using chocolate candies for this recipe.

Nutrition

Calories: 389kcal (19%)Carbohydrates: 57g (19%)Protein: 5g (10%)Fat: 16g (25%)Saturated Fat: 9g (45%)Polyunsaturated Fat: 1gMonounsaturated Fat: 5gTrans Fat: 0.3gCholesterol: 39mg (13%)Sodium: 153mg (6%)Potassium: 162mg (5%)Fiber: 2g (8%)Sugar: 31g (34%)Vitamin A: 253IU (5%)Vitamin C: 0.04mgCalcium: 36mg (4%)Iron: 2mg (11%)
Course: Dessert
Cuisine: American
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