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Ingredients You'll Need
Brownie base ingredients
Cookie ingredients
Notes and Substitutions
- Brownie mix: Use one regular box (about 18 ounces). Any brand works.
- Water: Swap with milk, buttermilk, or brewed coffee for richer brownies.
- Instant coffee: Optional, but it helps bring out the chocolate flavor and keeps brownies from tasting too sweet.
Tips for Best Brownies
- Let eggs come to room temperature, then lightly beat before adding. This helps everything mix evenly.
- Grease the pan and line with parchment so the brownies don't stick.
- Start checking with a toothpick about 2 minutes early. A few moist crumbs mean fudgy brownies; a cleaner toothpick means more cake-like.
- Let brownies cool before cutting. Chill them first if you want cleaner slices.
How to Make Cookie Brownie Bars from Brownie Mix
Step 1: In a bowl, combine:
- 3 tablespoons melted butter
- 2 tablespoons granulated sugar
- 2 tablespoons brown sugar
- 1 egg yolk
- ½ teaspoon vanilla extract
Mix until smooth.
Step 2: Add:
- ¼ teaspoon baking soda
- ¼ teaspoon kosher salt (use half for fine salt)
Stir until combined.
Step 3: Using a spatula, mix in ½ cup flour just until you don't see any dry flour left.
Step 4: Add most of the chocolate chips, saving a few to sprinkle on top later.
Step 5: Prepare the brownie batter according to the package directions and spread it evenly in a 9×9-inch pan.
Spoon dollops of cookie dough on top, gently spread them with a knife, then sprinkle the remaining chocolate chips over everything.
Step 6: Bake according to the package directions. If the cookie layer starts browning too fast, loosely cover the pan with foil.
Let the cookie brownie bars chill in the fridge for at least 1 hour before cutting.
Storage
Store the cookie brownie bars covered in the fridge for up to 5 days. Let them sit at room temperature for a few minutes before serving.
Recipe FAQs
Insert a toothpick into the brownie layer. A few moist crumbs mean fudgy bars. If it comes out wet, bake a few more minutes.
Yes. Bake them a day ahead and keep covered in the fridge. They slice cleaner after chilling.
It's best to store them covered in the fridge so the cookie layer stays firm and fresh.
More Tips for Boxed Brownies
If you're new to baking with brownie mix, this guide covers common questions, extra tips, and easy fixes.
Other Cakes and Baked Desserts You May Like
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📖 Recipe
Cookie Brownie Bars from Brownie Mix
Equipment
- 9x9-inch pan
Ingredients
Brownie layer
- 1 box brownie mix (about 18 ounces)
- Eggs room temp & lightly beaten (see box for amount)
- Water sub:milk, buttermilk, or coffee (see box for amount)
- Neutral oil (see box for amount)
- ½ teaspoon instant coffee or ¼ teaspoon espresso powder (optional)
Cookie layer
- 3 tablespoons melted butter salted or unsalted
- 2 tablespoons granulated sugar
- 2 tablespoons brown sugar light or dark
- 1 egg yolk
- ½ teaspoon vanilla extract
- ¼ teaspoon baking soda
- ¼ teaspoon kosher salt use half for fine salt
- ½ cup all-purpose flour
- ¼ cup bittersweet or semisweet chocolate chips (reserve some for topping)
Instructions
- In a bowl, mix melted butter, granulated sugar, brown sugar, egg yolk, and vanilla until smooth.
- Stir in baking soda and salt.
- Using a spatula, mix in flour just until no dry flour is showing.
- Add most of the chocolate chips, saving a few for the top.
- Prepare brownie batter according to the package directions and spread evenly in a 9×9-inch pan. Spoon dollops of cookie dough on top, gently spread with a knife, then sprinkle remaining chocolate chips.
- Bake according to the package directions. If the cookie layer browns too fast, loosely cover with foil.
- Let bars chill in the fridge for at least an hour before cutting.
Notes
- Brownie mix: Any brand works - follow the box directions.
- Water: You can use milk, buttermilk, or brewed coffee for richer brownies.
- Instant coffee: Optional, but makes the chocolate taste stronger and keeps bars from tasting too sweet.
- Line the pan with parchment so brownies don't stick.
- Start checking a few minutes early to avoid overbaking.
- A toothpick in the brownie layer with a few moist crumbs means fudgy bars.
- Chill before slicing for cleaner cuts.
Noah says
Very good and easy!!
Nora Reyes says
Yes! Thanks, Noah!
Tracey says
Stick with the homemade version. This may be "easier" but definitely does not come out that great.
Nora Reyes says
Hi Tracey, I totally understand—homemade from scratch is always great! This version is just an alternative for those who might want a quicker option. Everyone has their own preference. Thanks.
John says
My favorite combination of all time.
Nora Rey says
Oh, I hear you! Brookie brownies are the ultimate match made in dessert heaven! 🍪🍫🤩 The fudgy richness of brownies combined with the chewy delight of cookies is just unbeatable.