Crust: In a food processor pulse together the flour, powdered sugar, butter and salt until the butter is the size of rice. Slowly drizzle in the water while pulsing until it becomes a meal like texture.
Remove the dough and roll out until it is 1/8” thick and form it to an 8” tart pan.
Bake in the oven at 400° for 12-15 minutes or until lightly browned and cooked. Let cool.
Curd: In a large metal bowl over a medium size pot of boiling water whisk together the eggs, egg yolks, ¼ cup of sugar, zest of ½ lemon and juice of 1 lemon until it becomes very thick, like a custard, about 2 to 4 minutes. Be sure to constantly whisk.
Remove the bowl and whisk in the butter until it has melted. Cool the mixture in the refrigerator until completely cooled.
In a standing mixture with the whip attachment on high speed, mix the mascarpone and cream cheese until light and fluffy and then add in the remaining lemon zest, lemon juice, powdered sugar. Mix until combined and then fold in the chilled lemon curd.
Pour the mixture into the cooked pie shell and cool over night or until it firms up.