CAKE:

1. Preheat oven to 350F (177C). Brush the sides and bottom of an 8 or 9-inch cake pan with coconut or olive oil. Cut a circle of parchment paper to fit the bottom of the cake pan, place in the pan, brush with oil and set aside.
2. In a medium bowl, beat egg whites until stiff peaks form, set aside. 
3. In a small bowl whisk egg yolks, yogurt, stevia, vanilla and lemon zest, set aside.
4. In a large bowl, add almond flour, then add egg whites and egg yolk mixture, and fold gently to combine. Pour the cake mixture into the prepared pan and bake for 20 to 25 minutes, until a toothpick inserted in the center of the cake comes out clean.
5. Cool in pan for 10 minutes. Run a knife around the edge of the pan to loosen the cake. Invert cake to remove from pan and remove parchment paper. Reinvert the cake and transfer it to a wire rack to cool completely. Using a serrated knife, slice and serve with a spoonful of Lemon Curd.
   
   THE LEMON CURD:
6. In a medium saucepan off heat, whisk together eggs, stevia, vanilla and lemon zest. Add melted coconut oil, and whisk to combine. Finally, whisk in lemon juice.
7. Place pan over medium heat, whisking constantly, until mixture becomes opaque and begins to thicken, 1 to 2 minutes. Remove pan from heat and pour curd through a mesh strainer into a bowl.
8. Cool and serve. The lemon curd can be refrigerated in a covered container for 3 to 4 days.