Turn the oven to 350 degrees.

Place all of the shortbread ingredients into a bowl and mix together with your hands, gently rubbing the butter and flour between your fingers until you're left with a mixture that's the texture of damp sand.

It should stick together when you gently press it in your hands.

Do not over mix! When it reaches this point and there are little bits of butter still visible, you're done!

Grab a 9 inch springform pan, butter generously, and pour the crumbs into the base. Press them down until they are firmly packed. I chose to not build up the sides of the pan in order to show off the layers. You're welcome to do as you please, I'm nothing if not reasonable.

Bake for 15 minutes, or until very lightly browned. Let cool completely before assembling.

Meanwhile let's start the filling.

In a large bowl whip the cream cheese with the sugar and salt.

Whip this until it becomes very light and fluffy. Mix in 1/4 cup of the creme fraiche, and vanilla.

Transfer 2/3 of this mixture into a clean bowl.

To the other 1/3 of the cheesecake base, whip in the other 1/4 cup of creme fraiche, the zest, juice, and coloring. Coloring is optional, but it won't look very different when slicing without it.

Whip the cup of heavy cream until stiff peaks are formed.

Fold all of the whipped cream into the vanilla cheesecake base.

The lemon cheesecake base will keep it's thick, creamy texture: think the most amazing lemon bar you've had.

I used an acetate cake collar to line my springform pan, because I wanted clean layers. You can simply use a touch of butter along the outside rim of the pan, and before you un-mold warm the sides before releasing.

Layer the cheesecake fillings! I put the vanilla on the bottom, and topped with the lemon bar. Because these are not being baked, treat the fillings delicately. What you see is what you get. Literally.

Let this chill in the fridge for at least 6 hours, ideally overnight.