Lemon Protein Bars Recipe (12 grams per bar!) (2024)

Bright lemon flavor with a perfect shortbread crust, these lemon protein bars are the ultimate fun and delicious dessert bar! Made with high-protein collagen, the gooey lemon curd and buttery crust pack in 12 grams of protein per serving but the kicker is that no one even knows because they are THAT good! Try them yourself and find out why we’ve been eating them nonstop.

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I’m not sure if it’s a tick or not but when it’s super cold out, all I want is light, refreshing flavors that remind me of the warm west coast and sunny days. And the sun is yellow (ish) and lemon is yellow, therefore I want lemon during the depths of the tundra winter we are in. It’s this time last year when I went on a lemon kick making mylemon meringue pie with a biscuit base,Cayenne Lemon Ginger Shot, andLemon Ricotta Pasta.

It only makes sense that I would start on my lemon kick again now that it’s -9 out (not sure how that’s real??) so I got to work on this lemon protein bar recipe. Any time I attempt aprotein dessert recipe, it takes many iterations to get it right. This recipe I tested 4 separate times going from a true protein bar that tasted chalky and meh to the final test that tasted gooey, sweet, and tangy!

And I know these look thinner than store-bought, but there's thought behind this too! Growing up my dad raved about his mom's lemon bars that were thin all around but even top and bottom layers, so I put out a poll on Instagram to see what the crowd said. The people spoke - but if you want your bars thicker, just bake them in a smaller pan.

Why these high protein lemon bars will make you do the happy food dance

• Bursting with flavor, the type of flavor and tang that’s sour like a warhead but sweet enough that you keep coming back for another bite.
• 10 grams of protein per serving which in comparison, a normal lemon bar is only 2 grams. These also utilize almond flour and additional eggs for texture and the added bonus of more protein beyond just what comes from the collagen powder!
• A foolproof trickfor perfectly set lemon bars. I take the additional step of cooking the lemon curd on the stove top first to ensure it sets in the oven without any cracking.

Did this recipe put a smile on your face? Let us know! ⭐️→

recipe ingredients

You’ll need the following ingredients to make these tangy lemon bars.

notes

• Flour: We use a combination of all-purpose flour and almond flour to add texture and protein from the almonds.
• Sugar: Powdered sugar helps keep the shortbread crust tender while granulated sugar sweetens the curd.
• Unflavored collagen peptides: I prefer to use Orgain collagen peptides because it has 18 grams of protein per serving. It’s also completely flavorless and dissolves well.
• Salt: Fun fact, salt is biologically needed by our body so when we add a small amount of salt to foods, it heightens our senses, therefore making everything else taste stronger.
• Butter: Unsalted cold butter gets crumbled with the flour for the crust while the rest of the butter is melted into the curd.
• Eggs: I use a combination of whole eggs and egg yolks to create a luscious curd without using too much butter. Egg yolks contain more fat, thus making the curd creamier, plus it makes these bars a super yellow color! Keep those egg whites to make egg white wraps.
• Lemon: You will need lemon juice and lemon zest for lots of lemony flavor. I find it easiest to use store-bought lemon juice and 1 whole lemon versus squeezing all fresh lemon juice.
• Canned coconut milk: Adding just a little bit of cream at the end of cooking the curd in these lemon coconut protein bars helps to tame the acidity just enough. Just be sure to use a good canned coconut milk like Thai coconut milk. You would know if the coconut milk is not good because it will look curdled which means the fat and liquid have separated.

substitutions & variations

All substitutions are a 1:1 substitute unless otherwise noted. See recipe card for quantities.

• All-purpose flour —> 1:1 gluten-free flour replacement:I tested this recipe with gluten-free flour and it worked well. Just make sure it is a 1:1 gluten-free flour replacement (they should include xantham gum in the ingredients).
• Butter —> Vegan butter:A good quality vegan butter that formulated to mimic butter’s properties (not margarine) can be used for the recipe.Miyoko’sbutter is by far the best for baking. Margarine can be used for the curd but not for the crust because it melts too much which would mean the crust would spread and not hold together.
• Canned coconut milk —> Heavy cream: If you don’t have coconut milk, you can use vegan heavy cream or traditional heavy cream.
• Additions: If you feel called to mix it up, you can swirl in blueberry or strawberry jam to the top or mix in chia seeds for a lemon poppy seed vibe.

This recipe has not been tested with other substitutions or variations. If you replace or add any ingredients, please let us know how it turned out in the comments below!

how to make - keyword -(with photo & video!)

Be sure to scroll to the recipe card for the fulllemon protein bar recipe!

Step one: prepare

Separate out the egg yolks, measure out and zest your lemon, preheat the oven, and line your pan for the best results.

How to line a pan:Take two pieces of parchment paper and cut each one to the width of the pan, but keep them long enough that it will hang over. For an 8x8 pan, this works out to 2 pieces of parchment paper that are 7” x 12” each. To hold it down, use a chip clip or office clip to hold the parchment paper on the pan while filling it.

Step two: make the crust

Combine all the crust ingredients in a bowl, using your hands to rub together the butter and flour.

When is the dough ready?Shortbread dough is unique in that it never fully comes together until pressed. Your goal when combining everything is to get the texture to be like wet sand. Every bit should be coated but still loose and when squeezed between your hands, it should hold together.

Step three: bake

Press the shortbread dough into the prepared 8x8 pan, using your hands or offset spatula to really press it into the corners. Try to get it as even in thickness as possible. Bake for 16-18 minutes or until golden brown.

Step four: start the curd

While the crust bakes, in a cold, nonreactive pan, whisk together the sugar, eggs, and egg yolks until paste forms. Stir in the lemon juice and lemon zest. Heat over low to medium heat and cook while you keep stirring - don’t let it boil!

What is a non-reactive pan?This is a pan that won’t react with foods being cooked. Some examples are stainless steel, glass, and ceramic. Aluminum, cast iron, and copper are all reactive.

Step five: finish the curd

As soon as it heats up, add in the butter to melt it and stir in the collagen to dissolve it. Keep stirring until it thickens, about 5-7 minutes. Remove from heat and stir in the coconut milk.

How do I know the curd is thick enough? To check, dip a spoon in the curd and look at the back, wipe a swath away with your finger. The curd on either side should stay in place indicating that the curd is thick enough.

Step six: combine

Pour the lemon curd over the hot shortbread crust. Carefully tap the pan on the counter to remove any air bubbles. Then return to the oven for 12-15 minutes to cook until the filling is shiny and the center portion of the lemon bars wiggles like firm jello when you lightly tap the edges of the baking dish.Remove and let cool for an hour at room temperature and another 1-2 hours in the fridge.

expert tips

1. Don’t over-mix the eggs! If you overmix the eggs and create too many air bubbles which will cook fluffy instead of like a jelly-like curd. If you do over-mix, your lemon protein bars will look white on top but still be delicious. Just dust with some powdered sugar and
2. Mix the sugar and eggs first.This ensures the acid from the lemon juice won’t curdle the eggs.
3. Line your panto make sure you can get the bars out of the crust. You can also make them in a tart pan or other style pan with removable bases.
4. Chill the barsbefore cutting and serving. This allows the flavors to develop, the curd to truly set, and to help you get a clean cut. Otherwise, the curd will stick to your knife.

Can I use protein powder instead of collagen peptides?

No, collagen peptides and protein powder act totally differently. For more information, head over to our postcollagen peptides vs whey protein powderto learn more.

What do I do if the curd curdles?

So eggs can curdle because of two reasons. One is because of the acid in the lemon juice, and two because the curd cooked too fast and wasn’t stirred continuously. As long as it’s only a few flecks of curdled eggs, you can strain the curd. You might have a little less filling but enough to still make some amazing lemon bars!

Why are there white bubbles on the top?

This happens when the eggs are over-whisked. The little white dots are air bubbles that rise to the surface while baking. They don’t affect taste just appearance on your lemon bars.

Why put protein in lemon bars?

Protein is critical for our daily functionsand obviously eating protein lemon bars isn't the ideal way to eat the bulk of your protein. But in my experience, having a sweet treat that also has a higher protein count keeps me full (thus keeping me from eating a second and third bar) and makes a great post-workout snack that delivers fat, carbs, and protein. So why wouldn't I put protein in lemon bars??

Are these lemon bars healthy?

What is healthy varies greatly from individual to individual. If you are looking for a low carb, low sugar bite that you consider to be a healthy snack, then no, these are not it. But if you are looking for something with healthy fats from coconut milk, fiber from almonds, and protein to keep you satiated, then yes these are that.

Can I make these bars thicker?

Yup, cooking and baking is about preference so if you want these thicker, just bake them in a smaller pan.

troubleshooting & testing notes

I’m not sure my shortbread crust is mixed all the way.

Your crust is ready when all the butter has been crushed into small pebbles that resemble wet sand. The sure test is to squeeze it in your hand and it should hold together.

I tested these with protein powder and here’s what happened.

They were chalky and cake-like. I won’t lie - I still ate the whole pan but they were cracked on top and tasted more like lemon cake bars (if that makes sense). So please, don’t use protein powder.

I tested these with an all-almond flour crust and here’s what happened.

The crust was ok, but it was too soft and chewy. It also required a totally different ratio of ingredients so please don’t substitute the all-purpose flour for almond flour - it will not work.

how to store & meal prep it

fridge

These bars are best stored in the fridge for up to 2 weeks in an airtight container.

frozen

Lemon protein bars freeze beautifully! Simple wrap individually in plastic wrap and place inside of an air-tight container or plastic bag. Store them for up to 3 months in the freezer and don’t forget to label them with the date and what they are!

meal prep

Be like my grandma and make a double batch and freeze half! Because these freeze wonderfully, they are the best to keep in the freezer for last-minute guests.

reheating

Lemon bars are best eaten cold. To eat from the freezer, remove the bars and let them thaw at room temperature for 20-30 minutes before serving. The curd doesn’t fully freeze so it’s easy to thaw them quickly. You can also leave them in the fridge the night before serving.

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