Preheat the oven to 350 degrees °F and line an 8x8 baking pan with parchment paper and set aside.
In a large mixing bowl, add all ingredients for the crust: almond flour, tapioca flour, butter (or coconut oil), maple syrup (or honey), vanilla, and sea salt. Mix well until combined. Press evenly into the bottom of the prepared baking pan.
Bake for 25 to 30 minutes, or until crust is lightly brown. Meanwhile, prepare the lemon curd.
In a medium pot, place whole eggs, egg yolks, beet sugar (or maple sugar), lemon zest, lemon juice, and sea salt and whisk together.
Over low heat, whisk the lemon curd until it thickens and coats the back of a spoon, about 8 to 10 minutes. Be careful not to let it boil.
Remove from heat and strain through a fine mesh strainer into a medium mixing bowl. Add in the butter and stir until melted.
Pour the lemon curd over the crust. Bake for an additional 10 to 15 minutes until set.
Let cool completely, cover, and refrigerate for at least 3 hours to set.
Dust with powdered sugar, slice, and serve!
