Mascarpone Cheesecake Tart with Nectarines

Crust:
six 5"x 2-1/2" graham crackers
1-1/4 cups coarsely crushed amaretti (Italian almond macaroons, about 3 oz.)
3 tablespoons sugar
3 tablespoons unsalted butter, melted
Filling:
1-1/2 cups mascarpone cheese (about 3/4 lb. at room temp)
1/2 cup sugar
2 large eggs
1 tablespoon fresh lemon juice
2 teaspoons freshly grated lemon zest
1 teaspoon vanilla extract
1/4 teaspoon almond extract
3 tablespoons all purpose flour
1/4 teaspoon salt
For Topping
2 lbs. nectarines (about 8)
2 tablespoons sugar or to taste
Preheat oven to 3500. Lightly butter a 9" springform pan. Make crust.
In a food processor finely grind graham crackers and amaretti with sugar.
Add butter and blend until combined well. Press mixture onto bottom and
about 3/4" up the sice of pan. Bake crust in middle of oven 10-15 minutes
or until crisp and golden and cool completely in pan on a rack. Make
filling. In a bowl with an electric mixer beat mascarpone with sugar
until smooth and add eggs, 1 at a time. Beat well after each addition.
Beat in lemon juice, zest and extracts. Beat in flour and salt until
combined well. Pour filling into crust. Bake tart in middle of oven
30-35 minutes until pale golden and set. Cool completely in pan on rack.
Remove side of pan and transfer tart to a plate. Chill tart, covered at
least 4 hours and up to 24. Make topping just before serving. Slice
nectarines and in a bowl toss with sugar. Let nectarines stand, tossing
occaionally, until sugar is dissolved and juices are released, about 5
minutes. Mound topping on tart and serve immediately.