Allergy-Friendly Sunny Lemon Squares

Ah yes, the classic lemon square. It allows you to indulge in a wonderful balance of sweet, tart, a little crunch, and a silky smooth topping. Even better – it is perfect for springtime.

These Sunny Lemon Squares that I developed for Allergic Living break barriers in two ways. Importantly, they’re free of the nine top allergens and gluten-free, plus they are so simple to make. Trust me on this – these delicious beauties will quickly join the rotation of your baking must-dos.

The base of the squares is a classic (gluten-free) shortbread, and takes a few moments to put together. The longest step is melting and cooling the buttery spread. But no worries – you can do that in advance, then bake the shortbread base while squeezing those lemons. 

Once the lemons are juiced, the topping takes less than five minutes, and you’ll be so happy you made them. Do not be surprised if you find yourself licking the spatula after spreading the topping. 

Lemon Squares: Flours, Milk

To avoid a crumbly base, make sure you measure your flours properly (spoon and level, don’t scoop!). And for that filling? Any dairy-free milk will do, so choose what you’re already consuming in your kitchen. 

The pinch of turmeric is optional, of course, it just adds to the sunny hue. But if you don’t have it in the spice rack, no need to go buy a whole container. These squares will shine with the lemon juice anyway.

Leftovers, if you’ve ever entertained that word, can be stored in an airtight container in the fridge all week. These sturdy lemon squares are great for lunches, an after-work or after-school treat. Or you may even succumb to their lemony ways alongside your morning coffee. Enjoy!

Makes: 16 squares
Free of: Gluten and top allergens

See Also: Allergic Living’s Allergy-Friendly Spring Recipes


Ingredients for Lemon Squares

Shortbread Base
  • 2/3 cup sorghum flour
  • 1/2 cup tapioca flour
  • 3/4 tsp xanthan gum
  • ¼ tsp fine salt
  • ½ cup dairy-free, soy-free buttery spread (such as Earth Balance)
  • ¼ cup granulated sugar
  • 1 1/2 tsp vanilla extract
Lemon Filling
  • 1 1/3 cups dairy-free milk
  • 3/4 cup granulated sugar
  • Zest from 1 lemon
  • Pinch fine salt
  • Pinch turmeric (optional, for color)
  • 1/2 cup lemon juice (about 2.5 large lemons, freshly squeezed)
  • 6 tbsp cornstarch
  • 1 tsp vanilla extract
  • About 3 tbsp confectioners’ sugar, sifted

Instructions for Lemon Squares

  1. For the shortbread base, preheat the oven to 325 degrees F. Line an 8-inch square metal baking pan with parchment paper, leaving overhang on opposite sides for easy removal of the squares.
  2. Mix the sorghum flour, tapioca flour, xanthan gum, and salt together in a medium bowl. In a small pot or in a bowl in the microwave, melt the buttery spread until liquid in consistency, about 30 seconds. (Add 10-second intervals if not completely melted.) Then allow to cool to room temperature, about 20 minutes. 
  3. In a large bowl, combine the cooled buttery spread, sugar, and vanilla extract. Add flour mixture, and stir to create a clumpy dough. Transfer mixture into the pan and press the dough firmly into the bottom of the pan in an even layer.
  4. Bake the shortbread base for 15 to 18 minutes until firm to the touch. Remove from oven and let cool while preparing the filling. 
  5. To make the filling, first whisk together dairy-free milk, sugar, zest, salt, and optional turmeric in a medium saucepan. Keep whisking until smooth. Then put the lemon juice and cornstarch in a small bowl and whisk until that’s smooth. 
  6. Turn the stove under the saucepan to medium-high heat and bring filling ingredients to a simmer. Add the lemon juice mixture, whisking constantly to avoid clumping. Continue whisking for 2 minutes, until thickened. Remove from heat and stir in the vanilla extract. 
  7. Pour the lemon filling onto the shortbread crust. Spread evenly. Let stand at room temperature for at least 30 minutes until no longer steaming, then refrigerate to set completely, about three hours (or overnight).
  8. Dust the top with confectioners’ sugar just before serving. Now cut into 4 vertical rows, then 4 rows across to create your squares. Enjoy chilled or at room temperature.

Photo: Getty

Laurie Sadowski’s latest e-book is The Gluten-Free, Vegan, Allergy-Friendly Chocolate Chip Cookie Guidebook: For a limited time, Allergic Living readers get $5 off the e-book with the promotion code: Allergicliving