These oven baked peanut butter cookie blondie bars are the kind of easy dessert I love to make when I need something cozy, quick, and guaranteed to disappear fast. Whole Nutter Butter cookies get tucked into a simple peanut buttery blondie batter made with just a few pantry staples, and the result is a rich, chewy bar with little cookie surprises in every bite. It has that fun back-of-the-pantry magic that feels homemade and special without a lot of fuss.
Serve these bars slightly warm with a glass of cold milk, a scoop of vanilla ice cream, or a mug of coffee after supper. For a party tray, I like cutting them into smaller squares and setting them out with brownies and chocolate chip cookies so everyone can grab a favorite. They also pack nicely into lunchboxes or picnic baskets if you want a sweet little treat on the go.
Oven Baked 5-Ingredient Peanut Butter Cookie Blondie Bars
Servings: 16 bars
Ingredients
1 box Nutter Butter cookies, whole and unbroken
1 box yellow cake mix
2 large eggs
1/2 cup creamy peanut butter
1/2 cup unsalted butter, melted
Directions
1. Preheat your oven to 350°F. Lightly grease a clear glass 9x13 baking dish or line it with parchment for easier lifting later.
2. In a large mixing bowl, stir together the yellow cake mix, eggs, creamy peanut butter, and melted butter until a very thick batter forms.
3. Press about two-thirds of the batter into the bottom of the prepared baking dish in an even layer. It helps to lightly grease your hands or spatula since the batter will be sticky.
4. Arrange the whole Nutter Butter cookies in a single layer over the batter, fitting them snugly across the pan.
5. Drop the remaining batter in spoonfuls over the cookies, then gently spread as much as you can to cover most of the tops. It is fine if a few cookie edges peek through.
6. Bake for 25 to 30 minutes, or until the top is golden and the center is set. Let the bars cool completely in the pan before slicing into squares.
7. Cut into bars and serve, or chill them a bit first for cleaner slices and a firmer cookie layer.
Variations & Tips
Chocolate drizzle: Melt a little chocolate and drizzle it over the cooled bars for a peanut butter cup flavor that kids and adults both love.
Extra peanut butter flavor: Stir a handful of peanut butter chips into the batter if you want an even richer bar and a sweeter finish.
For picky eaters: Keep the top plain and skip any add-ins so the bars stay soft, simple, and familiar-looking for little ones who do not like surprises in dessert.
Cleaner slices: Let the pan cool completely, then chill for 30 to 60 minutes before cutting. A sharp knife wiped clean between slices makes the bars look especially nice.
Storage tip: Store the bars tightly covered at room temperature for up to 3 days, or in the refrigerator for up to 1 week. They are delicious either way.