Make these chewy M&M cookie bars in 30 minutes using just one bowl and 8 simple ingredients. No mixer and no chilling required. These cookie bars use a basic cookie dough without any baking soda or baking powder, keeping them ultra chewy instead of cakey with perfectly crisp edges. This M&M bars recipe is made in a square 8x8 inch pan and yields 16 squares.
Easy M&M cookie bars are guaranteed to be a family favorite. They are quicker and easier to make than individual cookies, making this a recipe perfect for beginners.
Also try Chocolate Chip Blondies and White Chocolate Raspberry Blondies for easy dessert treats.
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Ingredients needed to make M&M chocolate chip cookie bars
- Butter: Use unsalted butter for this recipe. If you only have salted butter, decrease the amount of salt by half. No need to bring the butter to room temperature before baking, as the butter will be melted.
- Brown sugar: Using brown sugar instead of white sugar helps keep these easy m&m cookie bars moist. Use light brown sugar or dark brown sugar for this recipe. I like to use dark brown sugar because it is what I usually have available and the extra molasses in the brown sugar gives the bar cookies a more caramely flavor. Be sure to pack the brown sugar into the measuring cup to get the correct amount. Do not substitute for granulated white sugar.
- Egg: You will need one large egg at room temperature. Be sure to remove the egg from the fridge at least 30 minutes prior to baking. It is important to bring the egg to room temperature because cold eggs do not incorporate as well into the cookie dough.
- Vanilla extract: I recommend using a high quality vanilla extract rather than imitation vanilla extract. Imitation extracts tend to have an artificial flavor or aftertaste that can alter the flavor of your baking.
- Salt
- All-purpose flour: Be sure to measure your flour using the scoop and level technique; scoop the flour from the container into the measuring cup without packing it in. Level off the top of the measuring cup with the handle of the spoon or a butter knife. This helps ensure your baking will not be overly dry or dense due to improperly measured or too much flour.
- M&Ms chocolate candies: I like to use plain m&ms / classic milk chocolate m&m candies here. Substitute with peanut butter m&m, christmas m&m or mini m&ms. This is a great recipe to use up leftover m&ms from Halloween or the holiday season.
- Semi-sweet chocolate chips: Using semisweet chocolate chips here helps balance the sweetness of the milk chocolate in the m&ms. I would not recommend substituting for milk chocolate chips or white chocolate chips, as these will make your cookie bars too sweet, even for the biggest sweet tooth.
Cookie bars are not just chocolate chip cookie dough in bar form. Therefore, you will notice there is no leavener such as baking soda or baking powder in this M&M cookie bar recipe, like there is in chocolate chip cookies.
This is because adding those ingredients will make the cookie bars more cakey than chewy. We want cookie bars with chewy centers, therefore no leavener is needed.
How to make chewy m&m cookie bars
Step 1
Preheat oven to 350°F. Line a square 8x8 inch baking dish with parchment paper. Square baking pans can be tricky to line with parchment paper.
I like to first spray the pan with nonstick cooking spray (or coconut oil spray). Then, lay a sheet of parchment paper over top of the baking pan.
Using scissors, cut in diagonally from each corner until the cut is about 1 inch past the corner of the pan.
After all corners have been cut, press down on the center of the parchment paper to fit the parchment into the pan. Tuck the flaps (the ones that look like triangles) behind so the parchment sits flat in the pan and along the edges.
You can use small binder clips to clip the parchment to the pan along the top of the pan, if desired. I find the parchment sticks well enough to the pan with the nonstick spray, so this is not always necessary.
Set the parchment-lined pan aside.
Step 2
Melt the butter in a small skillet over low heat or in a microwave-safe bowl. Be sure to cover the top of the bowl with a paper towel or wax paper before microwaving to prevent the butter from popping and exploding all over the microwave.
Step 3
In a large bowl, add the brown sugar and pour the melted butter over top. Whisk until well blended; the mixture will resemble wet sand.
Step 4
Add in the egg and vanilla and whisk to combine.
Step 5
Add in the dry ingredients (flour and salt), stirring with a wooden spoon until just blended and no dry flour spots appear.
Step 6
Stir in the M&Ms and chocolate chips.
Step 7
Scoop dough into the prepared baking pan and press gently into the corners of the pan using a spatula or clean hands to form an even layer.
If the dough is thinner in some areas and thicker in others, you will have uneven cookie bars. And, the thinner sections will bake faster thn the thicker sections leaving you with overbaked bars in spots and underbaked bars in other spots.
Sprinkle additional m&ms on top of the bars.
Step 8
Bake in the preheated oven for 20-25 minutes until edges are golden brown
Step 9
Cool bar cookies in the pan then lift out of the pan using the parchment overhang. Cut into 16 squares by cutting down the middle, then rotating the bars 45º and cutting down the middle again.
Wipe the knife clean in between cuts to get clean cuts. Now cut each of the halves in half again, rotating the cookie bars 45º and repeating. You will end up with 16 evenly sized squares.
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How to store m&m chocolate chip cookie bars
Once the cookie bars have cooled, store them in an airtight container at room temperature for up to 5 days. You may also place the cookie bars back into the metal pan and wrap the top in plastic wrap.
To freeze, place the cut squares on a parchment lined baking sheet in an even layer, spacing them apart so they are not touching. Place in the freezer for at least an hour then transfer frozen bar cookies to a freezer safe bag. Store in the freezer for up to 3 months. Thaw at room temperature before serving.
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Ingredients
- ½ cup unsalted butter
- 1 cup dark brown sugar packed
- 1 large egg room temperature
- 2 teaspoons vanilla extract
- 1 ¼ cups all-purpose flour
- ½ teaspoon salt
- ½ cup M&Ms chocolate candies plus more for sprinkling on top
- ½ cup semi-sweet chocolate chips
Instructions
- Preheat the oven to 350°F. Line a square 8x8 inch baking pan with parchment paper. Square baking pans can be tricky to line with parchment paper. I like to first spray the pan with nonstick cooking spray (or coconut oil spray). Then, lay a sheet of parchment paper over top of the baking pan. Using scissors, cut in diagonally from each corner until the cut is about 1 inch past the corner of the pan. After all corners have been cut, press down on the center of the parchment paper to fit the parchment into the pan. Tuck the flaps (the ones that look like triangles) behind so the parchment sits flat in the pan and along the edges. You can use small binder clips to clip the parchment to the pan along the top of the pan, if desired. I find the parchment sticks well enough to the pan with the nonstick spray, so this is not always necessary. Set the parchment-lined pan aside.
- Melt the butter in a small skillet over low heat or in a microwave-safe bowl. Be sure to cover the top of the bowl with a paper towel or wax paper before microwaving to prevent the butter from popping and exploding all over the microwave. Alternately, melt butter over low heat in a small saucepan, removing once the butter has completely melted.½ cup unsalted butter
- In a large bowl, add the brown sugar and pour the melted butter over top. Whisk until well blended; the mixture will resemble wet sand.1 cup dark brown sugar packed
- Add in the egg and vanilla and whisk to combine.1 large egg room temperature, 2 teaspoons vanilla extract
- Add in the flour and salt, stirring with a wooden spoon until just blended and no dry flour spots appear.1 ¼ cups all-purpose flour, ½ teaspoon salt
- Stir in the M&Ms and chocolate chips.½ cup M&Ms chocolate candies, ½ cup semi-sweet chocolate chips
- Scoop batter into prepared baking dish and press gently into the corners of the pan using a spatula or clean hands to form an even layer. If the dough is thinner in some areas and thicker in others, you will have uneven cookie bars. And, the thinner sections will bake faster than the thicker sections leaving you with overbaked bars in spots and underbaked bars in other spots. Sprinkle additional m&ms on top of the bars.
- Bake in the preheated oven for 20-25 minutes until edges are golden brown
- Cool bar cookies in the pan then lift out of the pan using the parchment overhang. Cut into 16 squares by cutting down the middle, then rotating the bars 45º and cutting down the middle again. Wipe the knife clean in between cuts to get clean cuts. Now cut each of the halves in half again, rotating the cookie bars 45º and repeating. You will end up with 16 evenly sized squares.
Notes
- Store cooled cookie bars in an airtight container at room temperature for up to 5 days. Alternately, place the cookie bars back into the metal pan and wrap the top in plastic wrap.
- To freeze, place the cut squares on a parchment lined baking sheet in an even layer, spacing them apart so they are not touching. Place in the freezer for at least an hour then transfer frozen bar cookies to a freezer safe bag. Store in the freezer for up to 3 months. Thaw at room temperature before serving.
Nutrition
