Small Batch Peanut Butter Brownies are homemade chewy fudge brownies made from scratch and baked in a loaf pan. Previously known as Fudgy Fluffernutter Swirl Brownies with a marshmallow fluff and peanut butter swirl.

Small Batch Peanut Butter Swirl Brownies In Loaf Pan

Decisions, decisions. They suck sometimes.

I’m not talking about choosing between chocolate and vanilla, cookies and brownies, or cheese and no cheese.

I’m talking about change.

Change is good. Change is scary. Change is risky.

And sometimes when the decisions leave you restless and confused inside, you don’t know which way to jump.

Being an adult is hard. But you know what isn’t hard?

Learning how to make these easy Small Batch Peanut Butter Swirl Brownies from scratch.

There are no decisions here. Chocolate peanut butter brownies with marshmallow fluff in one fudgy brownie.

See? No decisions. Just make them, eat them, and pretend the real world doesn’t exist.

Homemade Small Batch Peanut Butter Swirl Brownies from scratch

I love making homemade brownies because you only need one pot to make the batter. This brownie recipe uses cocoa powder so you don’t need to melt chocolate separately.

First, you melt the butter and peanut butter together. Then you whisk in the cocoa powder, sugar, salt.

At this point, the batter will be thick and grainy. Once you beat in the egg and vanilla, it’ll smooth back out.

Then you stir in the flour and peanut butter chips. Transfer to a loaf pan, swirl in more peanut butter and marshmallow fluff, and 20 minutes later, you have dessert.

I knew these brownies needed to be chewy and fudgy because I didn’t want to take the extra time to frost them. In fact, the peanut butter swirl on top acts like a “frosting”, which makes them ready to serve as soon as they cool.

All of this means you can whip up brownies at the last minute with little effort. Easy decision. The hardest part is deciding how many to eat.

Easy Small Batch Peanut Butter Swirl Brownies

Another decision that you don’t have to make is whether you should swirl in peanut butter or marshmallow fluff. Just swirl in both!

Fluffernutter refers to using both marshmallow fluff and peanut butter. Fluffer = marshmallow fluffer while nutter = peanut butter.

I originally published the recipe as Fudgy Fluffernutter Swirl Brownies, but not everyone was familiar with the term fluffernutter.

Hopefully renaming them to Small Batch Peanut Butter Swirl Brownies paints a better picture.

Small Batch Peanut Butter Swirl Brownies In Loaf Pan - Dessert For Two
There’s a saying that if you can’t make a decision, flip a coin because when it’s in the air, you’ll know how you want it to land. Maybe I’ll flip some brownies.

On second thought, maybe I’ll just eat them.

More Small Batch Brownie Recipes

Fudgy Fluffernutter Swirl Brownies |

Small Batch Peanut Butter Swirl Brownies In A Loaf Pan

Yield: 8 squares
Prep Time: 15 minutes
Cook Time: 20 minutes
Total Time: 35 minutes

Small Batch Peanut Butter Swirl Brownies are homemade chewy fudge brownies made from scratch and baked in a loaf pan.


  • 3 tablespoons unsalted butter
  • 5 tablespoons creamy peanut butter
  • 1/4 cup unsweetened cocoa powder
  • 1 cup granulated sugar
  • 1/4 teaspoon salt
  • 1 egg, room temperature
  • 1/2 teaspoon vanilla extract
  • 1/2 cup all-purpose flour
  • 1/4 cup peanut butter chips
  • 2 tablespoons marshmallow fluff


  1. Preheat oven to 350F. Lightly grease a 9x5 loaf pan and line with parchment paper.
  2. In a large saucepan, melt the butter and 3 tablespoons peanut butter.
  3. Remove from the heat and whisk in cocoa powder, sugar, and salt (batter will be thick and somewhat grainy).
  4. Whisk in the egg and vanilla.
  5. Switch to a rubber spatula and stir in the flour and peanut butter chips. Spread batter into the pan.
  6. In a microwavable-safe bowl or cup, warm the marshmallow fluff for 15 seconds or until easy to spread. Spoon onto of the brownie batter and swirl around with a knife. Repeat with the remaining 2 tablespoons peanut butter.
  7. Spread into the pan. Bake 18-20 minutes or until the edges pull away from the sides and the center doesn't look wet.
  8. Cool to room temperature then remove from the pan. If brownies stick, refrigerate until cold, bring back to room temperature, then try again. Store in an airtight container for up to 1 week.


Don't want peanut butter in your brownies? Check out my recipe for Small Batch Fudge Brownies made without peanut butter.

To make Brownie Ice Cream, follow the directions for my German chocolate ice cream using 4 ounces semisweet chocolate. Instead of adding frosting, add about half a pan of chopped brownies.

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