In a food processor combine crust ingredients. Divide mixture among prepared cheesecake cavities, adding one small cookie scoop to each. Press down firmly to create an even layer. Bake for 5 minutes.
Decrease oven temperature to 325°F.
In the bowl of a stand mixer, beat together cream cheese and sugar. Mix in sour cream, followed by lemon juice and lemon zest. Finally add egg, mixing until batter is smooth and streak free.
Add one heaping medium scoop to each cavity. Bake for 15-18 minutes. Cool in pan to room temperature. Transfer pan to refrigerator to chill cheesecakes thoroughly, at least 6-12 hours or more.
Prepare lemon curd. In a double boiler over simmering water, whisk all ingredients for 8-10 minutes. Press through a fine mesh strainer, into a small bowl. Cover with plastic wrap, pressing to the surface of lemon curd so to avoid a skin forming. Cool to room temperature. Place in refrigerator to cool completely and continue to thicken.
Carefully remove cheesecakes from pan, removing pan disc from the bottom of each crust. Using a piping bag fit with a small round tip or a spoon, carefully add a small amount (roughly 1-2 tsp) lemon curd to each cheesecake. Return to cheesecakes to refrigerator.
Prepare meringue. Add egg whites, sugar and cream of tartar to a metal stand mixer bowl over simmering water. Whisk for several minutes or until sugar is dissolved and whites are warm. Move metal bowl to mixer, beat on low increasing to high until mixture is stiff and glossy, roughly 5 minutes. Add vanilla, mixing in well. Transfer to a piping bag with desired tip, pipe onto chilled cheesecakes. Use a kitchen torch to lightly brown the meringue frosting.
Serve immediately. Store remaining cheesecakes in the refrigerator.