Grease a one layer cake pan. Can use a 8 inch or 9 inch. I used a 9 inch.
Zest all lemons. Reserve some zest for topping cake later.
Rub zest into sweetener
Mix flours, sweetener, salt, baking soda, xanthan gum together. Set aside.
Mix eggs, milk, sour cream, avocado oil, zest, lemon juice together.
Add dry ingredients to wet ingredients.
Mix just till incorporated.
Bake at 350 degrees for 35-40 minutes. Make sure to check at 30 minutes. (see notes)
If making a mini triple cake, use three 6 inch cake pans.
Use Parchment for the bottoms and spray the sides with baking spray or grease pans with coconut oil or oil of choice.