Active Time

　　30 min

　　Total Time

　　4 hr

　　

Ingredients

Makes 8 to 10 dessert servings

　　

For tart shell

12 (5- by 3-inch) graham crackers, coarsely crumbled

　　1 cup salted roasted peanuts (2 1/2 oz)

　　1/8 teaspoon ground allspice

　　1 stick (1/2 cup) unsalted butter, melted and cooled

　　

For filling and topping

4 oz cream cheese, softened

　　1/2 cup smooth peanut butter

　　3 tablespoons unsalted butter, softened

　　2 tablespoons dark brown sugar

　　1 cup chilled heavy cream

　　1/2 teaspoon vanilla

　　1/2 cup plus 1/3 cup Concord grape jam (9 1/2 oz)

　　2 cups red and green seedless grapes, quartered lengthwise

　　

Special Equipment

an 8- by 11-inch rectangular or a 10-inch round fluted tart pan with a removable bottom; a small offset spatula

　　

Make tart shell:

Step 1

Put oven rack in middle position and preheat oven to 350°F. Blend graham crackers, peanuts, and allspice in a food processor until nuts are coarsely ground. Transfer to a bowl, then add butter, stirring until crumbs are thoroughly moistened. Firmly press crumbs evenly over bottom and up sides of tart pan.

　　

Step 2

Bake shell until firm, about 10 minutes. Cool completely in pan on a rack.

　　

Make filling:

Step 3

Beat together cream cheese, peanut butter, and butter in a bowl with an electric mixer at medium-high speed until fluffy, about 1 minute. Add brown sugar and beat until incorporated. Beat cream with vanilla in another bowl until it holds soft peaks, then fold into peanut butter mixture gently but thoroughly.

　　

Assemble tart:

Step 4

Spread 1/3 cup jam onto bottom of tart shell with offset spatula. Spread peanut butter mixture on top with cleaned offset spatula. Chill tart, loosely covered with plastic wrap, until firm, at least 3 hours.

　　

Step 5

Just before serving, stir grapes with remaining 1/2 cup jam with a rubber spatula until coated. Spoon over tart.

　　Cooks' note:

　　Tart, without grape topping, can be chilled up to 12 hours. Top with coated grapes just before serving.