Spray bottom of 9 inch spring form pan with non-stick spray and line with parchment paper. Spray sides and line with a strip of parchment.

In the bowl of stand mixer, beat sugar, 1/2 cup butter, eggs, egg yolks and salt on high until creamy. Add lemon juice and beat until well combined. Mixture will curdle.

Transfer to a medium saucepan and heat over medium high heat, whisking constantly, until thickened and coats the back of a wooden spoon. About 4 or 5 minutes. Transfer to a shallow bowl, cover the surface with plastic wrap and chill until cold.

While lemon curd is cooling, prepare the crust by melting 1/3 cup butter in a saucepan, add graham crumbs and stir well to combine. Press crumbs into prepared pan and chill for 20 minutes.

To prepared filling combine mascarpone cheese and cream cheese and beat until light and fluffy, scraping sides of bowl as necessary. Add 1 1/2 cups of the prepared cold lemon curd and beat well. Spread over cooled prepared crust and smooth out to an even surface. Freeze for 30 minutes.

Remove from freezer and spread remaining lemon curd evenly over the top of cheese layer. Return to refrigerator and chill for 6 hours or over night.

To serve, carefully removed spring form pan and parchment, and decorate with fresh fruit or whipped cream