Sprinkle of Science

How to Make Peanut Butter Stuffed Brownies

How to Add Peanut Butter to Brownies

This is the fun part of this recipe! To get the best peanut butter flavor AND texture:

1. Prepare the pan. Line an 8×8-inch pan with parchment paper. Create an overhang so that you can lift the sheet of peanut butter out of the pan and place it back in the freezer while you mix up the batter.
2. Melt the peanut butter. Pour it into the prepared pan.
3. Freeze.  Place the pan of PB in the freezer until solid, about 1 hour.
4. Prepare the brownie batter as directed below. Pour half the brownie batter into the pan. Top the batter with the frozen sheet of PB, then pour the remaining batter on top. Bake immediately!
5. Please note: be sure to use conventional creamy peanut butter like Skippy or Jif. Any kind of “natural” peanut butter in which the oil separates won’t work in this recipe.

How to Make Fudgy Brownies

• The butter content in these brownies helps create a rich, fudgy brownie.
• The extra egg yolk adds even more richness.
• You’ll also notice there’s no baking soda or baking powder in this recipe. That’s because we’re making fudgy rich brownies, not cake.
• Whisking the eggs vigorously for a full minute as the recipe instructs will add enough air to slightly leaven the brownies without creating a cakey texture.
• Whatever you do, be sure not to accidentally over-measure the flour and cocoa powder. For perfect measurements and best results, weigh all ingredients with a digital kitchen scale.
• If you don’t have one, then lightly spoon each ingredient into the measuring cup and sweep off the excess. This will prevent you from compacting too much into the cup and creating dry brownies.
• Use a high-fat cocoa powder – learn more about high fat cocoa powders here.
• Don’t reduce the sugar – learn more about sugar’s role in baking brownies here.
• Additionally, try not to overbake your brownies to prevent them from drying out. I found the perfect bake time to be around 30 minutes in my oven.

Is Oil or Butter Better For Fudgy Brownies?

I recently experimented with Butter vs. Oil in brownies to see how the type of fat used affects the final result. The brownies made with butter were fudgier and softer than the oil brownies. There were also some shocking differences in the crusts of the two brownie batches! You’ll find this Peanut Butter Brownie recipe uses all butter for the perfect texture and flavor.

Check out my Butter vs. Oil in Baking article for a full breakdown of each of these fats and how they affect tenderness, flavor, and texture in baked goods (and not just brownies).

What Pan is Best For Baking Peanut Butter Stuffed Brownies?

• A square light-colored metal baking pan like this one is always my go-to for any brownie recipe.
• Metal (namely high-quality heavy aluminized steel or anodized aluminum) conducts heat more quickly and efficiently than glass or ceramic pans.
• Avoid metal pans that are darkly colored as they conduct heat too aggressively and will likely lead to burnt or dried edges.
• If you must use a glass or ceramic pan please note that the texture of the brownies may become gummy or overly dense and they’ll likely take significantly longer to bake. You run the risk of the center never cooking through with glass or ceramic.
• Learn more in my Glass vs. Metal Baking Pans article.

Are Peanut Butter Brownies Supposed to be Gooey in the Middle?

• I like my brownies to remain slightly gooey and soft in the middle. Especially these ones since they’re stuffed with peanut butter!
• However, they should still bake up so they’re safe to eat and solid enough to eat by hand once cooled and sliced.
• Make sure to allow your brownies to cool completely if they seem gooey.
• I love eating brownies chilled, especially in the summertime! Cold brownies are super fudgy – give it a try!
• You can always let them cool, cut into squares, then nuke in the microwave if you want them so gooey they require a fork to eat.

How to Store Peanut Butter Stuffed Brownies

• Brownies can be stored in an airtight container at room temperature for up to 3 days or in the fridge for up to 5 days.
• They’ll become more like a thick fudge in the fridge in the most delicious way.
• You can also reheat the brownies in the microwave until they’re gooey again, if you’d prefer.