Lemon Protein Bars Recipe (12 grams per bar!)

5 from 4 votes

Lemon Protein Bars Recipe (12 grams per bar!)

Bright lemon flavor with a perfect shortbread crust, these lemon protein bars are the ultimate fun and delicious dessert bar!

Prep Time10

Cook Time35

Cooling Time3

Total Time3 45

Course: Dessert

Cuisine: American

Keyword: bars, collagen, high protein, lemon

Servings:

Calories: 358kcal

Author: Mika Kinney

Equipment

1 large bowl
1 saucepan non-reactive (stainless steel, glass, or ceramic)
1 8x8 baking dish if you want thicker bars, opt for a smaller pan

Ingredients

Shortbread Crust

⅔ cup all purpose flour
⅓ cup almond flour not almond meal
⅓ cup powdered sugar plus a little more for dusting the top
¼ teaspoon salt
¼ cup collagen peptides unflavored
⅓ cup butter unsalted and cubbed, preferably room temp

Lemon Curd

¾ cup sugar granulated
3 eggs
3 egg yolks
¼ teaspoon salt
1 cup lemon juice
juice and zest from 1 lemon
3 tablespoon butter unsalted or vegan butter
½ cup collagen peptides unflavored
¼ cup coconut milk canned or heavy cream

Instructions

Prepare

Separate out the egg yolks, measure out and zest your lemon, preheat the oven to 350 degrees, and line your pan. Set your butter out to come to room temperature.

Make the crust

Combine all the crust ingredients in a bowl, using your hands to rub together the butter and flour until it resembles wet sand.
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.
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.

Make the curd

While the crust bakes, in a cold, nonreactive pan, whisk together the sugar, eggs, and egg yolks until paste forms. Make sure you do this first otherwise the lemon juice will curdle your eggs! 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.
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. If for some reason it appears to curdle, you can strain the curd after cooking.
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.

Combine & bake

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. Slice, top ith confectioners sugar and enjoy!

Video

Notes

Expert Tips

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.
Mix the sugar and eggs first. This ensures the acid from the lemon juice won’t curdle the eggs.
Line your pan to 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.
Chill the bars before 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.

Common Questions:

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 post collagen peptides vs whey protein powder to 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.

Nutrition