Extract the juice, pulp, and zest from 1 large lime.

Lime curd
Combine in a saucepan and heat until thickened:
3 egg yolks
1/2 c sugar
4 T lime juice

Remove from heat, add:
pinch of salt
3 T butter in pieces

Stir until mixed, let cool.

Cheese custard
Beat until foamy:
3 egg whites
1/4 c sugar
4 oz mascarpone
3 T lime juice

1 c. graham cracker crumbs
4 T melted butter

Press into springform pan. Spread custard evenly. Bake at 350F for 20 minutes.
Cover with lime curd and bake 5 more minutes.
Remove from oven and cool. Cover with whipped cream.