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stack of peanut butter blondies

peanut butter blondies stacked on a white plate

wet ingredients for peanut butter blondies in a glass bowl with a colorful whisk

peanut butter blondie batter in a glass bowl with Reese's Pieces

hands sprinkling Reese's Pieces onto peanut butter blondie batter in a baking pan

peanut butter blondies on a white plate

Forever loving these extra soft peanut butter blondies, an ode to the 1st recipe ever published on my website! They’ve been a hit for years and we now add even more Reese’s Pieces. If you need an excuse to make them, these are always a hit alongside hot chocolate in the wintertime or at a pool party in the summertime. And they fly off the plate when I serve them at bridal showers, baby showers, for Father’s Day, graduation parties, or Halloween celebrations. (But do you really even need an occasion to bake peanut butter blondies?!)

More Blondies to Love:

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peanut butter blondies stacked on a white plate

Peanut Butter Blondies

  • Author: Sally
  • Prep Time: 10 minutes
  • Cook Time: 30 minutes
  • Total Time: 3 hours
  • Yield: 18 large blondies 1x
  • Category: Dessert
  • Method: Baking
  • Cuisine: American


Soft, simple, and delicious peanut butter blondies made in only 1 bowl!


  • 3/4 cup (1.5 sticks or 170g) unsalted butter, melted and slightly cooled for 3 minutes
  • 2 cups (400g) packed light or dark brown sugar
  • 3/4 cup (194g) creamy peanut butter
  • 2 large eggs + 1 extra egg yolk
  • 1 Tablespoon pure vanilla extract (yes Tablespoon!)
  • 2 cups (250g) all-purpose flour (spoon & leveled)
  • 1 teaspoon baking powder
  • 1 teaspoon salt
  • 1 and 1/4 cups Reese’s Pieces


  1. Preheat the oven to 350°F (177°C) and grease a 9×13 inch pan or line with aluminum foil or parchment paper, leaving an overhang on the sides to lift the finished blondies out (makes cutting easier!). Set aside.
  2. In a large bowl, whisk the melted butter and brown sugar together until combined. Whisk in the peanut butter, then add the eggs, egg yolk, and vanilla. Whisk it all until completely combined.
  3. Add the flour, baking powder, and salt. Fold the batter together using a rubber spatula. Batter is very thick. Finally, fold in the Reese’s Pieces. Spread evenly into prepared pan and sprinkle with a couple additional Reese’s Pieces on top for looks, if desired.
  4. Bake for 30 minutes, then test the blondies with a toothpick. Insert it into the center of the pan. If it comes out with wet batter, the blondies are not done. If there are only a few moist crumbs, the blondies are done. Keep checking every 2 minutes until you have moist crumbs. My blondies take 30 minutes. They taste a little dry if you overbake!
  5. Remove from the oven and place on a wire rack to cool completely before cutting into squares.
  6. Cover and store leftover blondies at room temperature for up to 1 week.


  1. Freezing Instructions: Blondies freeze well up to 3 months. Thaw overnight in the refrigerator, then bring to room temperature before serving.

Keywords: peanut butter blondies, blondies

Thank you for a life-changing 5 years and many more to come! xo

Reader Questions and Reviews

  1. Unfortunately these did not bake up well at all. I think there may be too much butter in the recipe? I baked for an hour which resulted in the tops of the blondies being overdone but the bottoms were completely raw.

  2. Loved this recipe – only change was i reduced the sugar to 1.5 cups . Topped it off with bitter ganache to balance the sweetness and it was a hit. Thank you so much Sally for the effort you put into testing recipes and posting them!

  3. You used to have Valentine’s Day peanut butter blondies. What happened to that recipe? It was perfect

    1. Hi Taylor, we recently removed that older recipe from our site. If you email us at, we’d be happy to share a copy with you. Thank you!

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