To make the crust, combine almonds, unsweetened coconut flakes, stevia, lemon zest in a food processor. Pulse until the the almonds are ground but not too fine.
Place crust contents into a bowl and mix in 1/4 cup softened coconut butter. The crust should be slightly moist.
Pour crust into an 8x8 inch baking pan lined in parchment paper.
To make the filling, add coconut oil and coconut butter to a small saucepan and melt over medium low heat for a few minutes until they are melted. Whisk in the stevia (or honey) and lemon zest.
Then, take the filling off the heat and let cool for 1-2 minutes. Add the lemon juice to the coconut mixture and stir together. You do not want to add the lemon juice to liquid when it is hot because it will seize up a lot.
Pour the lemon coconut filling over the crust. Top with additional lemon zest if desired.
Refrigerate for at least an hour or until ready to serve. To speed up the process, place in the freezer.
I suggest lining the baking pan with parchment paper or even foil as it will help to remove and cut the coconut lemon squares.