Line a 9x3 inch baking pan with baking parchment and set aside.
In a medium seized bowl combine the flour, sugar, almond flour, melted butter and vanilla and stir until just about smooth
Spread out the mixture in the lined pan and level with your hands
Bake the crust in a pre-heated oven 180 C (350 F) for 20-25 minutes or until the base is golden brown
Whilst the crust is cooking, zest and juice the lemons and tip in a food processor along with the eggs, corn flour, butter and salt. Blitz until just mixed, be sure not to over mix.
When the base is ready, reduce the temperature of the oven to 150 C (300 F). Pour the lemon topping on the base and bake for another 25 minutes. The topping would be slightly jiggly but will solidify on cooling.
Once cool completely, cut into squares, top with icing sugar serve. They can be stored in the refrigerator, in an airtight container for 4-5 days.