
About a month ago, I attempted a Vegan Lemon Squares recipe.
It failed…as in miserably!!
If you follow Pedaler’s Plate, maybe you remember seeing a Sour Lemon Popsicle? Anyone? Well, those were the result of the first failed lemon filling, which I then froze because the filling just wouldn’t set! [Those popsicles turned out delicious, by the way — be sure to check those out.]
Since then, I’ve had yet another failed take on vegan lemon squares. What is the deal? The filling was, again, too jiggly! Ugh.
Nobody wants jiggly vegan lemon squares!
The good news is, in failing twice, I nailed a delicious, healthy vegan crust that will be my go-to from now on. It’s really good, and gluten-free! We’ll get to that later!
But guys!! FINALLY! Fi. Na. Leeee.

I stumbled onto a Vegan Lemon Squares recipe that worked and is finally shareable! Warning though: these are very SWEET. The recipe I adapted for the filling came from Veganomicon, with a few substitutions. It was their ratios that worked best in the end, so I’d like to give them credit for being part of the process!
After trying several versions of squares that used coconut cream as the base, this Vegan Lemon Squares recipe nixes the coconut altogether and incorporates agar agar. So it’s much lower in fat that my first two attempts.
Why do we have to say “agar” twice? I’m not sure! Let me know if you look up the etymology.
Agar agar is the vegan alternative to gelatin. It’s 100% seaweed! Much like jello, when it’s heated and allowed to cool, it creates a gelatinous mold of sorts. It was just enough to hold this lemon baby together!

Lemony, Sugary Sweetness…Still Working on It
I’m not gonna lie — this recipe has more sugar than I like to use, but I believe even clean eaters need a break from clean every now and then. Enjoy this!
In the meantime, I’m going to keep playing with the ratios of agar agar more, and I’ll get back to you if I can reduce the sugar!

The sunny, bright yellow color of Vegan Lemon Squares comes from a combination of the lemon juice, lemon zest, and a small sprinkle of dried turmeric. Turmeric looks orange before it’s cooked, but as soon as it hits heat, it begins to yellow. So don’t worry about the orange!
A Delicious, Fool-Proof Tart Crust
The crust is really nice. I could eat it plain as a raw cookie, and it’s only 4 ingredients!
You’ll need a high speed blender like a Vitamix or plan to buy already blitzed oat flour. It’s super easy to make your own oat flour, though. Simply take old-fashioned oats, put the dry oats into a blender, and crank up the volume. In seconds, you’ll have finely ground oat flour.
Then you add almond flour, coconut oil, and maple syrup! Check out the ratios below. Hope you enjoy!

Vegan Lemon Squares
Ingredients
For Crust
- 2 cups old-fashioned oats, blended to oat flour in a high speed blender
- 1 cup almond flour
- 1/3 c coconut oil, melted
- 1/3 c maple syrup
For Lemon Filling
- 1 1/3 cup water
- 1.5 T agar agar powder
- 1 1/4 cups sugar
- 1/8 tsp turmeric (optional, this turns is a more saturated bright yellow color)
- 2/3 cup fresh squeezed lemon juice
- 3 T corn starch
- 1-2 T fresh lemon zest (about 2 lemons' worth)
- 1/4 c non-dairy milk, I used unsweetened almond
Instructions
For Crust
- Preheat oven to 350.
- For the crust, first blend the old-fashioned oats down to oat flour using a high speed blender. Add the almond flour, coconut oil, and maple syrup and start on low to combine. Pulse as needed, scraping down the sides to incorporate all the ingredients.
- Line a 9×13 dish with parchment paper. Spoon out the crust from the blender into the dish, and press evenly into the bottom of the pan. Push it up the sides a little to make an outer shell for the filling to have a border.
- Bake the crust for about 10-15 minutes. This will be the only baking involved, so allow the crust to get a little toasty brown, then remove from the oven to cool.
For the Lemon Filling
- Soak the agar agar in the water for 15 minutes, in a small sauce pan.
- Zest the lemons and squeeze enough juice to fill 2/3 cup.
- Mix the corn starch into the lemon juice and stir to incorporate.
- After the agar agar has sat in water for 15 minutes, bring the mixture to a boil for about 10 minutes to let the agar dissolve. Then add the sugar and turmeric, and allow those to boil together for another few minutes, until sugar is dissolved, as well.
- Turn down the heat, and then add the corn starch/lemon juice mixture, stirring as your pour. Add the lemon zest and non-dairy milk now, too. Whisk or stir as it simmers on low, as it thickens. It takes about 5 minutes to get thicker.
- Remove pan from the heat, and pour the mixutre into the baked crust. Allow the whole dish to return to room temperature first, then refrigerate it for at least 4 hours, even better if overnight.
- After being refrigerated, the lemon squares should be firm enough to slice and serve. Best if served immediately from refrigeration. Return any unused tart to the fridge, as the tart will get softer when exposed to warmer outdoor temperature.
I love this cookie crust cut into squares and served as a stand alone or with fruit. Thanks! It passes Molly’s gluten free taste test.
Yay! I am also a fan of the crust, it’s so EASY! The lemon squares are honestly a little sweet for me for a daily treat! But the crust I could munch on indefinitely.