I’ve been making lemon squares for years; including all the years I’ve been gluten free. Tried a few recipes; okay but my clear favorite for taste and easiness to make is the one out of my beloved “Gluten-Free Baking Classics” by Annalise Roberts; cannot stress enough how reliable and tasty her stuff bakes up. This one definitely falls into both those categories.
I used the wonderful Meyer lemons my brother sends me; so delicate a flavor and perfectly scented. Use whatever lemons you have as this is a delightful treat that even your non-gf friends will clamor for.

Lemon bar with lots of powdered sugar!
“The” Lemon Squares
Crust:
1 cup King Arthur basic gf blend flour
¼ c sugar
1 tsp. xanthan gum
5 Tbsp. butter.
Heat oven to 350 degrees. I put the oven shelf near the bottom of the oven. In your stand mixer, blend flour, sugar and gum; add butter which you cut up into 8-10 smaller pieces. Blend until small crumbles. While it does that spray an 8 inch metal pan with cooking spray and dust with gf flour. Pour crumbs into pan and spread evenly as possible into corners and up a bit of the sides. Press a bit but not too hard to get the best result. This recipe’s filling doesn’t go very far up the sides so just a bit up. Bake 15 minutes.
While it bakes make the filling; I use the same mixing bowel and paddle. FYI: I Have a great new paddle with a scraper edge that my guy bought me; it is fantastic at mixing batters better; far less scaping necessary. Best gift in kitchen!
3 large eggs
¾ cup sugar
2 Tbsp. KA basic gf blend flour
½ tsp. baking powder
1/8 tsp. salt
2 tsp. grated fresh lemon rind; then juice it for
1/3 cup fresh lemon juice (2 lemons should do it)
½ tsp. pure lemon extract
Beat eggs in the mixing bowl after the crust goes into the pan until kinda foamy. Then add rest of ingredients and mix well; be sure the flour is blended in. Pour over the warm crust and bake for 20 more minutes. Let cool before cutting. I like to sprinkle mine with a bit of powdered sugar; 1-2 tbsp worth.
I think it tastes even better the second day. Needs to rest a bit and let the flavors ripen to their fullest.