Mix together the crust ingredients and press into the bottom and sides of a well-greased spring-form pan.
Set aside.

Beat egg yolks until very thick.
Add 1/2 cup sugar.
Beat until fluffy.
Add softened cream cheese to egg mixture.
Add in lemon rind.
Mix thoroughly.

Beat egg whites and salt until soft mounds form.
Add 1/2 cup sugar, 2 Tbsp. at a time.
Continue beating until stiff peaks are formed.

Gentle fold together the two egg mixtures until thoroughly blended.
Turn  mixture into crust lined spring-form pan.
Bake at 350° for 45 - 50 minutes. *
Cool on a rack.

*Take it out of the oven while it is still slightly soft in the middle. If you overcook it, it will be grainy textured.