Mix all of the dry ingredients together. Add the grated lemon zest, vanilla extract, egg and melted butter and mix until well combined.
Press into an 8" x 8" baking pan lined with quality baking paper.
Bake for 20 minutes and remove from oven. Meanwhile prepare the filling.
Prepare The Lemon Topping
Beat the eggs till well combined. Add remaining ingredients and beat until well combined but take care not to over aerate.
Pour the filling straight over the base, even if it is hot, and return to the oven straight away. Bake for a further 20 minutes and allow to cool on the bench for an hour.
Refrigerate for 1-2 hours before slicing into approximately 20 bars.
Store in the fridge.
I have given the option of using desiccated coconut in the base if you would like to have a bit more texture and coconut flavor. Simply switch the coconut flour for the desiccated coconut.
Garnish with a dusting of low carb confectioners sweetener or some grated lemon rind and shredded coconut.If the shortbread base is a little dry, simply add 1 or 2 more tablespoons of melted butter. This can occur due to some brands of coconut flour and/or almond flour/almond meal being dryer than others.