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Soft & Gooey Protein Blondies (With 10g Protein)

If you’re a fan of soft, chewy blondies but also trying to up your protein intake, these protein blondies are about to become your new favorite dessert.

Stack of protein blondies

Imagine biting into a thick, gooey blondie that melts in your mouth and is studded with rich chocolate chips. Now, imagine that same blondie packing 10 grams of protein with only 145 calories.

It sounds too good to be true, but these protein blondies are the real deal. Let them be proof that you don’t have to sacrifice flavor or texture to enjoy a protein-packed treat that fits your macros.

Dunking protein blondie in milk

On my quest to create the perfect protein cookie recipe, I recently struck gold with my protein cookie skillet. It’s like a giant, gooey chocolate chip cookie cake loaded with protein – what’s not to love?

I knew I had to remix that recipe into high-protein blondies, and let me tell you, the result is simply irresistible.


Ingredients needed for protein blondies

The key to these protein blondies is using a combination of whey/casein protein powder, oat flour, and almond flour. This trio of ingredients creates the perfect soft and chewy texture that you want in a blondie.

I like to use a peanut butter-flavored protein powder to really drive home the peanut butter flavor, but you could easily swap it out for vanilla if you prefer a more neutral blondie base. Just make sure you’re using a blend of whey and casein for the best texture – using all whey can result in a drier, more crumbly blondie. As is the case with all my recipes, I stick with PEScience protein powder.

Oat flour is my secret weapon in most of my protein cookie recipes. It lends a soft texture and slightly sweeter flavor that you just can’t get with all-purpose flour. And almond flour adds a subtle nuttiness and helps keep the blondies moist. For anyone with nut allergies, you can just use more oat flour in place of almond flour, but the end result may not be as soft.

Of course, it wouldn’t be a blondie without brown sugar. It’s what gives these protein blondies that classic rich, caramel-y flavor. I like to use a brown sugar substitute to keep the calories in check, but regular brown sugar works just as well.

To keep these blondies extra moist and gooey, I added some unsweetened applesauce to the batter as well. It’s a great way to add moisture without adding a ton of extra calories or fat with butter or eggs.

And let’s not forget the mix-ins. I went with classic chocolate chips, but you could easily swap them out for white chocolate, peanut butter chips, or even chopped nuts. The world is your oyster!

How to make protein blondies

Making these protein blondies is a breeze. You don’t need any fancy equipment or ingredients – just a couple of bowls and a spoon or spatula.

Start by mixing together your wet ingredients in a large bowl – that’s your peanut butter, light butter (I used Country Crock Original), and unsweetened applesauce. The mixture doesn’t have to be perfectly smooth, but you’ll want to mix everything together until combined.

In a separate bowl, mix together your dry ingredients – protein powder, oat flour, almond flour, brown sugar substitute, baking soda, and salt.

Add your dry ingredients to the bowl with the wet ingredients and mix everything together until you have a thick, albeit slightly sticky, cookie dough.

Lastly, fold in your chocolate chips (or whatever mix-ins you’re using).

Protein blondies in pan before baking

Spread the batter into a prepared 8×8 baking dish. You can line the pan with parchment paper to make it easy to lift the blondies out later (like with my protein brownie recipe), but cooking spray works just as well here.

The key to getting those perfect gooey blondies is to underbake them just slightly. I found that 12-15 minutes at 325°F is the sweet spot, but keep an eye on them. You want the edges to be lightly golden and the center to look a bit underdone.

Protein blondies in pan after baking

Let your blondies cool in the pan for at least an hour before slicing. I know it’s torture to wait, but trust me, it’s necessary. They’ll continue to set up as they cool, giving you that perfect dense, chewy texture. The blondies may look too cakey when they first come out of the oven, but you’ll see the center sink as it sets.

Once they’re cool, slice them into 16 squares and dive in!

Sliced protine blondies

If you want larger blondies, you can opt for fewer slices, but 16 total protein blondies worked great for these.

For reference, if you decide to slice these into 12 total blondies, each one will contain 190 calories and 13 grams of protein, which is still very impressive for decadent blondies!

Single protein blondie

Tips for the best protein blondies:

  • Use a blend of whey and casein protein powder for the best texture. If you only have whey, you can try using a bit less than the recipe calls for to avoid dryness.
  • Don’t overbake your blondies! Err on the side of underbaking for the gooiest texture. Remember, the ingredients are all safe to eat raw, so a little underdone is okay.
  • Let your blondies cool completely before slicing for the cleanest cuts. If you can’t resist digging in while they’re warm, just know they’ll be a bit messier and gooey inside (but just as delicious).
  • Store your blondies in an airtight container, preferably in the fridge. These will remain fresh at room temperature, but the texture is more “authentic” when stored in the fridge due to some extra firmness. When stored at room temperature, the exterior tends to soften.

Stacked protein blondies


More protein-packed cookie recipes to enjoy

If you’re loving these protein blondies, be sure to check out some of my other favorite high-protein cookie recipes:

But these are just the tip of the protein cookie iceberg- check out all of my protein cookie recipes here.


Single protein blondie

Soft & Gooey Protein Blondies

Yield: 16 Blondies
Prep Time: 5 minutes
Cook Time: 14 minutes
Additional Time: 1 hour
Total Time: 1 hour 19 minutes

What's not to love about blondies? They are thick, soft, square cookies that can be enjoyed like brownies. But let's take it to the next level: let's make protein blondies with 10 grams of protein each and only 145 calories.



  1. Preheat your oven to 325 degrees F.
  2. In a large bowl, whisk together the peanut butter, light butter, and applesauce.
  3. In a separate bowl, mix together all of the dry ingredients except for the chocolate chips.
  4. Add the dry ingredients to the wet ingredients, then mix together until cookie dough forms.
  5. Fold in the chocolate chips.
  6. Lightly spray an 8x8 baking dish with cooking spray (or use parchment paper) and then add the cookie dough to the pan. Use your hands to press the dough so it reaches each corner and is roughly the same thickness throughout.
  7. Bake at 325 degrees for 12-15 minutes. The exact baking time will depend on your oven, the type of pan you use, and your preferred doneness. This is a recipe that you can safely underbake if you prefer extra chewy blondies. For reference, I baked mine for exactly 14 minutes.
  8. Remove the pan from the oven and allow the blondies to cool for one hour. The center of the pan will be way too soft right out of the oven, but it will set and firm up as it cools, so give it one full hour before slicing.
  9. Slice into 16 blondies, then dig in!
  10. For the best texture, keep leftovers stored in the fridge. These protein blondies also hold up great in the freezer and remain soft enough to bite into right out of the freezer.


  • Leftovers can be kept fresh at room temperature in an airtight container, but the exterior of the blondies tends to soften. For the most authentic blondie texture, these are best stored in the fridge to retain their firmness. The freezer also works very well.
  • I have only tested this recipe with a whey/casein protein blend- if you use 100% whey protein, these will be much drier. As far as flavor, this can be customized however you'd like. I love using peanut butter flavor, but vanilla also works as a neutral base.
  • This is the same base recipe I used for my protein cookie skillet, so you can follow that recipe if you want to make a smaller alternative to a full batch of blondies.
  • I do not count zero-calorie sugar substitute in my carb totals. If you are super strict about carbs, you may want to factor those in.
  • All of the ingredients in this recipe are safe to eat raw, so don't be afraid to underbake these.
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    Nutrition Information
    Yield 16 Serving Size 1 Blondie
    Amount Per Serving Calories 145Total Fat 9gCarbohydrates 9gProtein 10g

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    Sunday 19th of May 2024

    Any alternatives to almonds and oat flour?

    Matt Rosenman

    Wednesday 22nd of May 2024

    I use those are a little more "macro friendly" options to regular AP flour. You can likely use regular flour in their place but it will change things a bit. Almond flour adds some extra fat & moisture, so the end result may be a little bit cakier.

    About Matt Rosenman

    With over 15 years of experience in health and fitness, Matt Rosenman is the expert voice behind Matt’s philosophy is simple: no foods are off-limits, and a healthy lifestyle shouldn't be complicated or restrictive. As a former certified personal trainer with a bachelor’s degree in Health Behavioral Sciences, Matt brings well-rounded expertise to his blog. From revamping classic recipes with a nutritious twist to breaking down fast food menus, his goal is make healthy living less confusing for everyone. Featured in major publications and with a strong following on social media, Matt is committed to making “healthy” uncomplicated—no matter where you are in your health journey. Join Matt on his mission to simplify health without sacrificing flavor. Learn More

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