Peanut Butter Brookies (Cookie Brownies)

Jump to Recipe

These Peanut Butter Brookies (Cookie Brownies) bring together all that is good about a fudgy brownie and a peanut butter cookie. The two mixtures are made separately before swirling together to create a marbling effect! The result is a rich chocolate brownie with generous bites of peanut butter cookie!

This recipe starts with my classic brownie base, which gets a dreamy Peenie B shake up by combining with a peanut butter cookie dough. The brownie batter and cookie dough get added to the pan like a marble cake, with the two batters swirled together for a fusion bake!

For these brownies, we rely heavily on the melted butter and light brown sugar to give the fudgy texture and super shiny topping. To make the shiny top on a brownie, there are arguments as to whether it’s the egg, or the molten sugar in the butter, so let’s make sure to do both. This recipe cuts neatly into 9 pieces, but could be sliced smaller. If serving a crowd, I’ll cut each square into 2 triangles, giving 18 pieces. Plus, the recipe is easily doubled. They keep well for a few days. That said, they don’t last long if you’ve got lots of happy hungry mouths in the house!

WHEN IT COMES TO MAKING THE BEST BROWNIES, HERE ARE A FEW TIPS TO KEEP IN MIND:

1. Quality Ingredients: Always use high-quality ingredients in your brownie recipe. This includes using good quality chocolate, cocoa powder, and fresh eggs. It will make a noticeable difference in the taste and texture of the brownies.
2. Don’t Overmix: When combining the ingredients, be gentle and avoid overmixing the batter. Overmixing can lead to a denser and tougher texture. Mix until the ingredients are just combined.
3. Proper Pan Size: Use the recommended pan size mentioned in the recipe. Using a smaller or larger pan can affect the baking time and the texture of the brownies. For fudgy and moist brownies, an 8×8-inch square baking pan is usually recommended.
4. Do Not Overbake: Keep a close eye on the brownies while they are baking and avoid overbaking them. A slightly underbaked brownie will be fudgy and moist, while an overbaked one can turn out dry. Insert a toothpick into the center – if it comes out with a few moist crumbs, the brownies are done.
5. Let Them Cool: Allow the brownies to cool completely in the pan before cutting and serving. This helps them to set and ensures that they hold their shape. It also allows the flavors to develop fully.
6. Experiment with Additions: Feel free to get creative with your brownie recipe by changing up the chocolate chips/chocolate chunks, or by adding nuts or fruit. Just make sure not to overload the batter, as it may affect the texture.

Remember, practice makes perfect when it comes to baking brownies. Don’t be afraid to make tweaks and adjustments to the recipe to suit your preferences. You can totally shift the frosting quantity for more or less, just do what suits you! 

INGREDIENTS REQUIRED 

There are no specialist ingredients or equipment required for this bake. I can find everything I need at my local supermarket or grocery store. Also, I use a standard 8 inch square tin for almost all of my traybake recipes for ease. If you do want to convert to 9 inch, you’ll need to play with the quantities a little or they will be too thin. To line a square baking tin, cut two pieces of baking paper that are just narrower than the width of the tin (less than 8 inches wide). Then place one on top of the other in opposite directions, so that all four edges of the tin are covered. This will make removing the bake so much easier! 

• Dark/Semi-Sweet Chocolate, Melted
• Unsalted Butter
• Light Brown Soft Sugar
• Granulated Sugar
• Large Free Range Eggs
• Vanilla Extract
• Plain (All Purpose) Flour
• Cocoa Powder
• Peanut Butter

TOP TIPS FOR THE BEST Peanut Butter Brookies (Cookie Brownies)

• Melted Butter: As mentioned above, this contributes to the shiny top!
• Melted Chocolate: Try to use a higher quality dark chocolate where possible, as this really does contribute to that final flavour.
• Light Brown Sugar and Granulated Sugar: It is the combination of both sugars that creates the fudgy texture and rich flavour.
• Cocoa Powder: Again, where possible try to use a higher quality make. This contributes so much to the flavour and I find some cheap ones really dull the richness! 
• Peanut Butter: Make the cookie dough entirely separate. I find the cheaper/basic peanut butters make the best cookie dough when compared to natural varieties. That said, feel free to use whatever you prefer or already have to hand.
• Assembly: Add scoops of the brownie batter and cookie dough alternately to the pan. Then swirl together just a little using a knife. You want the end result to have big cookie dough bites rather than it all turning into one mixture.

For my Peanut Butter Brookies (Cookie Brownies), I use a basic 8′ square pan (I like this one). I also recommend a good stand mixer or high speed mixer (like this one) to make the brownie mixture. If you want more wild brownie recipe ideas, check out my Oreo Frosted Brownies. For videos and baking inspiration, head on over to my Instagram. If you make this recipe, don’t forget to drop it a star rating, leave a review or share a photo on your socials! 

STORAGE FOR MY Peanut Butter Brookies (Cookie Brownies)

Because these brownies don’t use a fresh frosting, place in an airtight container and keep in a cool place like your cupboard or pantry. They will keep for up to 3 days this way. A cake tin is a great option if you have one. 

Alternatively, you can freeze the brownies. Completely wrap as tight as you can using cling film/Saran wrap. If you have an airtight container too, place it in there before freezing. Let thaw in the fridge before serving. I like to give them a quick 10-15 second blast in the microwave before eating for that extra gooeyness.