Blend flour, powdered sugar, almond extract and salt in processor. Add butter and process until moist clumps form. Gather dough together. Press dough into 11-inch diameter tart pan with removable bottom. Freeze crust until firm, about 20 minutes.
Preheat oven to 425°F Line crust with foil; fill with dried beans or pie weights. Bake crust until sides are set and beginning to color, about 15 minutes. Remove foil and beans. Bake crust until cooked through and pale golden, piercing with fork if crust bubbles, about 10 minutes longer. Cool crust completely. Reduce oven temperature to 350°F.
Blend almonds, almond paste and sugar in processor until nuts are finely ground. Add eggs, cream, lemon juice and lemon peel and process until blended. Pour into prepared crust.
Bake tart until filling is set and golden, about 40 minutes. Cool tart in pan on rack. (Can be prepared 1 day ahead. Cover and refrigerate. Let stand at room temperature 30 minutes before serving.).
Push bottom of pan up, releasing tart. Place tart on platter. Arrange berries decoratively atop tart. Cut into wedges. Serve with whipped cream.