Nectarine and Mascarpone Tart in a Gingersnap Crust

My husband doesn't eat chocolate; a crime I know. So, I always find myself looking for dessert recipes sans chocolate. This one was a definite winner. After finally finding the mascarpone in this tiny town, I was able to make it and it was well worth the effort.
Nectarine and Mascarpone Tart in a Gingersnap Crust

From Smitten Kitchen

Crust
3 1/4 cups gingersnap cookies, coarsely broken
6 Tbs. unsalted butter melted (I needed 8 Tbs.)

Filling
1 8-oz. container mascarpone cheese
6 oz. cream cheese, room temperature
1/4 Cup sour cream
1/4 Cup sugar
1 tsp. grated lemon peel
1/4 tsp. vanilla extract
1 Tbs. finely chopped crystallized ginger (the recipe says it is optional, but I don't think so)

Topping
4 to 5 small nectarines, cut into thin slices
1/4 Cup peach jam, warmed
2 Tbs. finely chopped crystallized ginger (the recipe says it is optional, I didn't put it in here)

For Crust
Preheat oven to 350 Degrees. Finely grind gingersnaps in processor. Add butter and blend until crumbs are evenly moistened. Press mixture over bottom and up sides of a 9 inch tart pan with a removable bottom. Bake crust until color darkens, pressing sides with the back of a spoon if it begins to creep down in the pan, about 8 minutes. Cool completely.

For Filling
Beat first 6 ingredients in a medium bowl until smooth. Beat in crystallized ginger. Spread filling into crust. Cover loosely and refrigerate at least 2 hours and up to 1 day.

For Topping
Overlap nectarine slices on top of the filling in concentric circles. Brush with warm jam. Sprinkle with crystallized ginger. Serve or refrigerate up to 6 hours.