Peanut butter lovers, this one’s for you. These Peanut Butter Protein Blondies bake up thick, soft, and perfectly chewy with just the right amount of sweetness. They pack in a solid dose of protein without tasting “healthy,” so they work just as well for dessert as they do for a midday snack.
You’ll only need one bowl and a few pantry staples. If no-bake treats are more your speed, you might also like these easy make-ahead options: Blueberry Oat Protein Bars or the classic combo in Peanut Butter Chocolate Protein Bars.
Peanut Butter Protein Blondies - Soft, Chewy, and Satisfying
Ingredients
Method
- Prep the pan: Heat oven to 350°F (175°C).Line an 8x8-inch pan with parchment, leaving overhang for easy lifting.
- Make oat flour (if using): Blend oats in a blender until fine and floury. Measure after blending.
- Whisk wet ingredients: In a large bowl, whisk peanut butter, eggs, applesauce, milk, and vanilla until smooth.
- Add dry ingredients: Stir in protein powder, oat flour (or AP flour), brown sugar, baking powder, and salt. Mix just until combined.Batter will be thick.
- Fold in extras: Gently fold in chocolate chips or nuts if using.
- Spread and smooth: Transfer to the lined pan and smooth the top. Sprinkle a few extra chips on top for looks.
- Bake: 16–20 minutes, until edges are set and a toothpick comes out with a few moist crumbs. Do not overbake.
- Cool and slice: Let cool in pan for at least 20–30 minutes.Lift out, then cut into 12 blondies.
What Makes This Recipe So Good
- High protein, great texture: Soft and fudgy center with golden edges—no dry, chalky bite.
- One-bowl simple: Minimal mess and easy cleanup. Perfect for busy weeks.
- Pantry-friendly: Peanut butter, oats or flour, eggs, and protein powder are likely already on hand.
- Customizable: Add chocolate chips, swap sweeteners, or go gluten-free without fuss.
- Meal-prep ready: They hold well, freeze well, and taste great chilled or warmed.
Shopping List
- Natural creamy peanut butter (well-stirred)
- Vanilla or unflavored whey or plant protein powder
- Old-fashioned oats (blended into oat flour) or all-purpose flour
- Light brown sugar or coconut sugar
- Eggs
- Unsweetened applesauce or mashed ripe banana
- Milk of choice (dairy or non-dairy)
- Vanilla extract
- Baking powder
- Salt
- Optional mix-ins: chocolate chips, chopped peanuts, or a sprinkle of flaky salt
Step-by-Step Instructions
- Prep the pan: Heat oven to 350°F (175°C).
Line an 8×8-inch pan with parchment, leaving overhang for easy lifting.
- Make oat flour (if using): Blend oats in a blender until fine and floury. Measure after blending.
- Whisk wet ingredients: In a large bowl, whisk peanut butter, eggs, applesauce, milk, and vanilla until smooth.
- Add dry ingredients: Stir in protein powder, oat flour (or AP flour), brown sugar, baking powder, and salt. Mix just until combined.
Batter will be thick.
- Fold in extras: Gently fold in chocolate chips or nuts if using.
- Spread and smooth: Transfer to the lined pan and smooth the top. Sprinkle a few extra chips on top for looks.
- Bake: 16–20 minutes, until edges are set and a toothpick comes out with a few moist crumbs. Do not overbake.
- Cool and slice: Let cool in pan for at least 20–30 minutes.
Lift out, then cut into 12 blondies.
Storage Instructions
- Room temperature: Store in an airtight container for up to 2 days.
- Refrigerator: Keeps 5–6 days. Texture stays fudgy; great chilled.
- Freezer: Wrap individually and freeze up to 3 months. Thaw at room temp or microwave 15–20 seconds.
Health Benefits
- Protein to keep you satisfied: Protein from peanut butter and powder helps manage hunger between meals.
- Healthy fats: Peanuts provide monounsaturated fats that support heart health when enjoyed in balance.
- Fiber boost: Using oat flour adds fiber, which supports digestion and steady energy.
- Lower sugar option: You can reduce added sugar or use a lower-sugar protein powder without losing flavor.
What Not to Do
- Don’t overbake: Pull them when the center looks just set.
Overbaking leads to dry, crumbly bars.
- Don’t pack the flour: Measure oat flour or AP flour lightly; too much will make the blondies dense.
- Don’t skip salt: A pinch balances sweetness and boosts peanut flavor.
- Don’t use dry, powdery peanut butter: Stir natural peanut butter well or the batter will be stiff.
Variations You Can Try
- Chocolate swirl: Melt a little chocolate and swirl over the batter before baking.
- Peanut crunch: Fold in chopped roasted peanuts for extra texture.
- PB&J blondies: Dollop your favorite jam on top and swirl lightly.
- Banana bread vibe: Use mashed ripe banana instead of applesauce and add cinnamon.
- Different protein treats: For more snack ideas, check out these no-bake bites: No Bake Brownie Batter Protein Bites and bright, tangy No Bake Lemon Protein Bites.
- Breakfast-friendly: If you prefer spoonable snacks, try this creamy option: High Protein Brownie Batter Dip.
FAQ
Can I make these gluten-free?
Yes. Use certified gluten-free oats to make oat flour, or a trusted 1:1 gluten-free baking blend. Check that your protein powder is gluten-free as well.
What kind of protein powder works best?
Whey isolate blends bake up tender and moist.
Plant protein works too, but it absorbs more liquid—add a splash of milk if the batter looks dry.
Can I replace the sugar?
You can use coconut sugar, a reduced amount of maple syrup (cut back on milk slightly), or a granulated sweetener you like. Taste the batter and adjust as needed.
How do I know they’re done?
The edges will look set and lightly golden, and the center will no longer look glossy. A toothpick should come out with a few moist crumbs, not wet batter.
Can I make them egg-free?
A flax egg can work, though the blondies may be a touch denser.
Let them cool fully before slicing to help them set.
Wrapping Up
These Peanut Butter Protein Blondies hit that sweet spot between treat and everyday snack. They’re simple to throw together, easy to customize, and perfect for meal prep. If you’re building a weekly snack lineup, you might love these too: High Fiber Oat Protein Bites and creamy, quick Protein Peanut Butter Mousse.
Happy baking and snacking!
