Chocolate Chip Cookie Bars are an easy way to enjoy soft, chewy cookies in bar form. These bars are rich with brown sugar and chocolate flavor and stay moist and delicious for up to ten days when stored properly.
Why you’ll love this recipe
This one‑bowl recipe makes chewy chocolate chip bars without an electric mixer. You get all the flavor of a classic chewy chocolate chip cookie with the convenience of a tray bake—easy to make, slice, and share.
These bars stay tender long after baking. The secret to their lasting chewiness is mini marshmallows: they melt into the batter while baking and leave behind a soft, chewy texture that keeps the bars moist for days.
Chocolate chip cookie bars are ideal for care packages, school lunches, or a week of snacks. If you need them to travel or be mailed, leaving the bars uncut in a disposable pan helps them retain moisture and makes them sturdier for shipping.
Ingredients
This overview lists the main ingredients. The full measurements and step‑by‑step instructions are in the printable recipe card below.
Instructions
This is a short overview of the method. The complete instructions are in the recipe card below.
- Melt the butter in a medium bowl.
- Stir together the melted butter with sugar, salt, and vanilla.
- Beat in the eggs, one at a time, then stir in the flour and baking powder until combined.
- Fold in toffee bits, chocolate chips, and mini marshmallows.
- Spread the batter evenly into a lightly greased 8″ x 8″ or 9″ x 9″ pan.
- Bake at 350°F (175°C) until the top is golden and a toothpick comes out mostly clean.
- Cool completely before cutting to ensure neat slices.
Storage
Store cooled bars in an airtight container at room temperature for up to 10 days.
For mailing or longer holds, leave the bars uncut in a disposable pan to help them stay moist and travel better. If mailing cut bars, place parchment between pieces and double wrap before placing them in an airtight container or freezer‑weight bag.
Tips and variations
- Make the bars in either an 8″ or 9″ square pan. An 8″ pan yields a thicker bar and may require a few extra minutes of baking time.
- Dark brown sugar adds deeper molasses flavor, but light brown sugar works fine if that’s what you have.
- Swap semi‑sweet chips for milk or dark chocolate to change the chocolate intensity.
- Substitute M&M’s for toffee bits to make colorful candy cookie bars.
- Use chopped nuts instead of toffee bits for more crunch and flavor variation.
- For best texture, use regular mini marshmallows. Vegan marshmallows may puff and create air pockets during baking.
More chocolate chip treats
Try other chocolate chip recipes for different textures and flavors: biscotti for a crisp dunkable cookie, peanut butter chocolate chip bars for a rich, chewy bar with peanut flavor, or pumpkin chocolate chip cookies when you want something seasonal and soft.
Chewy Chocolate Chip Bars
Ingredients
- ½ cup unsalted butter melted
- 1 cup brown sugar packed
- ½ teaspoon salt
- 1 ½ teaspoons vanilla extract
- 2 large eggs
- 1 ½ cups all-purpose flour
- 1 ½ teaspoons baking powder
- 1 cup toffee bits
- ½ cup semi-sweet chocolate chips
- 1 cup mini marshmallows
Instructions
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Preheat oven to 350°F. Lightly grease an 8″ x 8″ or 9″ x 9″ baking pan with butter or nonstick spray.
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Melt the butter in a medium bowl.
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Stir the brown sugar, salt, and vanilla into the melted butter.
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Beat in the eggs one at a time until incorporated.
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Add the flour and baking powder and mix until just combined.
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Fold in the toffee bits, chocolate chips, and mini marshmallows.
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Spread the batter evenly in the prepared pan.
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Bake 20–25 minutes until the top is golden brown.
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Allow the bars to cool completely before cutting.
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Store bars in an airtight container at room temperature for up to 10 days.
Notes
Mailing bars uncut in a disposable pan helps them stay moist and makes shipping easier. If you must mail cut bars, place parchment or wax paper between pieces, double wrap in plastic, and place in an airtight container or freezer‑weight zip bag.
Nutrition
First Published: January 12, 2014. Last Updated: March 4, 2023.