If you love classic chocolate chip blondies but want something a little more fun, these Blondies Bars are it. They use the same basic idea—simple cookie-style dough baked in a pan—but with a few small upgrades that make them taste like a modern bakery treat, not a boxed mix. We’re talking shredded coconut, chocolate chunks, and mini marshmallows, all baked into a soft, chewy base.
This version is designed for real life: it uses basic pantry ingredients, comes together in one bowl with a mixer, and makes a big batch in a sheet pan. It’s great for parties, potlucks, or stocking the freezer for quick desserts. I’ll walk you through each step so you know exactly what the batter should look like and how to bake them so they stay soft and fudgy instead of dry and cakey.
Your New Go-To Recipe: Blondies Bars
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The Required Ingredients
- 2 cups salted butter, at room temperature
- 1 1/2 cups granulated sugar
- 1 1/2 cups light brown sugar, firmly packed
- 4 large eggs
- 1 tablespoon vanilla extract
- 1 teaspoon coarse sea salt
- 1 teaspoon baking soda
- 4 1/2 cups all-purpose flour
- 1 cup shredded sweetened coconut
- 2 cups chocolate chunks
- 1 1/2 cups mini marshmallows
- Optional: flaked sea salt for sprinkling on top
How to Make It Happen
- Preheat your oven to 350°F (175°C). Line a 15x10x1-inch rimmed baking pan with parchment paper, letting it hang over the edges for easy lifting later. Lightly coat the parchment and sides of the pan with nonstick spray. This helps the blondies release cleanly and prevents sticking at the corners.
- Add the room-temperature butter, granulated sugar, and brown sugar to the bowl of a stand mixer fitted with the paddle attachment. Beat on medium-high for about 2 minutes, until the mixture looks light, creamy, and slightly fluffier. If it still looks dense or grainy, keep mixing for another 30 seconds.
- Turn the mixer to medium speed. Add the eggs one at a time, mixing well after each addition so the batter looks smooth before adding the next egg. Mix in the vanilla, coarse sea salt, and baking soda until everything is evenly combined and the batter looks glossy.
- Switch the mixer to low speed. Gradually add the all-purpose flour, about 1/2 to 1 cup at a time, letting it mix in before adding more. Stop mixing as soon as you no longer see dry flour. Over-mixing here can make the bars tough instead of soft and chewy.
- Turn off the mixer and add the shredded coconut, chocolate chunks, and mini marshmallows. Use a spatula or wooden spoon to fold them in by hand until they’re evenly distributed. The dough will be thick and heavy, more like cookie dough than cake batter.
- Scrape the dough into the prepared pan. Use an offset spatula or the back of a spoon to spread it into an even layer, pushing it all the way to the edges and into the corners. Try to level the top so it bakes evenly and doesn’t have high or low spots.
- Bake for about 25 minutes, until the edges are golden brown and the center looks just set but still slightly soft and pale. The middle should not look wet, but it should have a little jiggle if you gently nudge the pan. This is key for a fudgy, not dry, texture.
- If you like a sweet-salty finish, immediately sprinkle a small pinch of flaked sea salt evenly over the top while the blondies are still hot. Let the pan cool completely on a wire rack before cutting. Cutting too early will make the bars fall apart because the marshmallows and chocolate are still very soft.
- Once fully cooled, lift the blondies out using the parchment overhang and cut into 48 bars (6 rows by 8 rows), or larger squares if you prefer.
Getting That Fudgy Center
The biggest difference between chewy, fudgy Blondies Bars and dry, cakey ones is baking time. These bars should be pulled from the oven when the edges are nicely golden and the center looks set but still soft. If the top is firm and evenly brown all the way across, they’re probably over-baked. Remember, they continue to cook a bit in the hot pan as they cool.
Another key detail is mixing. Cream the butter and sugars thoroughly, but once the flour goes in, stir just until there are no dry patches. Over-mixing at this stage develops gluten, which makes the texture bready instead of dense and rich. Finally, let the bars cool fully before slicing. This helps the melted chocolate and marshmallows firm up, giving you clean, moist squares instead of crumbly pieces.
Easy Mix-In Ideas
You can easily adjust these Blondies Bars with whatever you have in your pantry. If you’re low on chocolate chunks, use regular chocolate chips, chopped chocolate bars, or even a mix of dark and milk chocolate. Just keep the total amount close to the original so the bars hold together well and don’t turn into a pile of melted chocolate.
For a twist, swap some of the chocolate for chopped nuts like walnuts or pecans for crunch. You can also replace the coconut with finely chopped toasted nuts or leave it out for a plainer bar. Colored sprinkles, butterscotch chips, or white chocolate chips all work too. Try not to add more than an extra 1/2 cup of mix-ins beyond the recipe amount or the dough may struggle to bake evenly in the center.
FAQ: All You Need to Know
Can I halve this recipe if I don’t need a full sheet pan of blondies?
Yes, you can halve the recipe very easily. Use half of every ingredient and bake the batter in a 9×13-inch pan lined with parchment and lightly greased. The thickness will be similar, but you should start checking for doneness around 20 minutes since a smaller pan can bake a bit faster. Look for the same cues: golden edges and a just-set center. Let them cool fully in the pan before cutting so they don’t fall apart.
Why do my blondies sink in the middle after baking?
Blondies can sink for a few reasons. One common cause is under-baking the center, especially with a thick batter and lots of mix-ins like marshmallows. The middle needs to be just set; if it looks shiny and wet when you pull it, it will likely collapse as it cools. Another issue is over-creaming the butter and sugar, which can whip in too much air and cause the bars to rise and then deflate. Finally, make sure your oven is fully preheated and avoid opening the door too often, which can drop the temperature and affect structure.
How should I store and freeze these Blondies Bars so they stay soft?
Once the blondies are fully cooled and sliced, store them in an airtight container at room temperature for up to 3 days. For the best texture, place a small piece of parchment between layers so they don’t stick. To keep them longer, freeze the cut bars in a single layer first until firm, then transfer them to a freezer bag or container. They’ll keep well for about 2–3 months. You can thaw at room temperature or warm individual bars in the microwave for 10–15 seconds to bring back that soft, fresh-baked feel.
Blondies Bars
Equipment
- Stand mixer with paddle attachment
- 15x10x1-inch baking pan
- parchment paper
Ingredients
- 2 cups salted butter room temperature
- 1 1/2 cups granulated sugar
- 1 1/2 cups light brown sugar firmly packed
- 4 large eggs
- 1 tablespoon vanilla extract
- 1 teaspoon coarse sea salt
- 1 teaspoon baking soda
- 4 1/2 cups all-purpose flour
- 1 cup shredded sweetened coconut
- 2 cups chocolate chunks
- 1 1/2 cups mini marshmallows
- flaked sea salt optional, for sprinkling
Instructions
- Heat the oven to 350°F (175°C). Line a 15x10x1-inch baking pan with parchment paper and lightly spray or grease the pan; set aside.
- In the bowl of a stand mixer fitted with the paddle, beat the room-temperature butter with both sugars on medium-high for about 2 minutes until the mixture is light and fluffy.
- Reduce speed to medium and add the eggs one at a time, mixing thoroughly after each addition. Stir in the vanilla, coarse sea salt, and baking soda until evenly incorporated.
- Switch the mixer to low and gradually add the flour, mixing just until the dough comes together—avoid overworking the batter.
- Fold in the shredded coconut, chocolate chunks, and mini marshmallows by hand until evenly distributed throughout the batter.
- Spread the batter evenly into the prepared pan and bake until the edges are golden and the center is set, about 25 minutes. Take care not to overbake to keep the bars moist.
- If desired, sprinkle flaked sea salt over the hot bars. Let the blondies cool completely in the pan before lifting out with the parchment and cutting into squares.
