M&M Cookie Bars

These easy M&M Cookie Bars are soft, chewy and packed with M&Ms and chocolate chips. An easy treat perfect for lunchboxes and parties!

Prep Time 15

Cook Time 25

Total Time 40

Servings squares

Calories 245kcal

Author Samantha Pickthall

Ingredients

130 g unsalted butter melted
1 3/4 cups (210g) all-purpose flour
2 tsp cornstarch
1/2 tsp baking soda
1/2 tsp salt
1/2 cup granulated sugar
1/2 cup lightly packed light brown sugar
1 large egg, at room temperature
1 tsp vanilla extract
1 cup regular M&Ms
1/4 cup chocolate chips

US Customary - Metric

Instructions

Preheat the Oven: Preheat the oven to 350ºF (180ºC). Line a 9-inch square baking pan with parchment paper, leaving an overhang on the sides to easily lift the cookie bars out after baking. Set aside.
Melt the Butter: Melt the butter in a small saucepan over low heat, stirring occasionally. Alternatively, melt in the microwave in 30-second intervals.
Cool the Butter: Pour the melted butter into a large mixing bowl and allow it to cool for 10 minutes until it is only slightly warm. Ensure it does not firm back up.
Combine Dry Ingredients: In a medium mixing bowl, whisk together the flour, cornstarch, baking soda, and salt until evenly combined. Set aside.
Mix Sugars: Add both sugars to the slightly warm melted butter and whisk for 20 seconds until well combined.
Add Egg and Vanilla: Add the egg and vanilla extract and whisk until smooth and fully incorporated, about 15 seconds.
Add Dry Ingredients: Add the flour mixture and use a rubber spatula or wooden spoon to fold and mix until a thick cookie dough forms.
Add M&Ms and Chocolate Chips: Add the M&Ms and chocolate chips and mix until evenly distributed throughout the cookie dough.
Transfer to Pan: Transfer the dough into the prepared baking pan and press it into an even layer using a spatula. The dough will be thick.
Bake: Bake for 21-23 minutes or until the edges are lightly golden and a toothpick inserted into the centre comes out with a few moist crumbs attached. Do not overbake, as the cookie bars will become dry. Slightly underbaking helps create a soft and chewy texture.
Cool: Remove from the oven and allow the cookie bars to cool in the pan for 30 minutes. If desired, gently press extra M&Ms and chocolate chips into the top while they are still warm. Carefully lift the bars out using the parchment paper overhang and transfer to a wire rack to cool completely before slicing.

Video

Notes

Store: Keep M&M Cookie Bars in an airtight container at room temperature for up to 5 days. For the best soft and chewy texture, keep them well covered when not serving.

Freeze: Once completely cooled, place cookie bars in a freezer-safe airtight container or zip-top bag with parchment paper between layers. Freeze for up to 3 months.

Thaw: Allow frozen cookie bars to thaw at room temperature before serving. For a freshly baked texture, warm individual bars in the microwave for a few seconds before enjoying.

Nutrition