Preheat oven to 400 degrees F. Combine flour, ground nuts, the 1/4 cup sugar, and salt. Cut in butter until mixture resembles small peas. Add egg and toss until just moist, adding 1 tablespoon water, if necessary.
Form dough into a ball; press evenly onto bottom and up sides of a 10-inch tart pan. Bake for 10 minutes. Remove from oven. Reduce oven temperature to 375 degrees F.
Meanwhile, in a large saucepan combine cranberries, orange juice, and 1/3 cup water. Cook and stir over medium heat until skins of berries begin to pop. Stir together the 1-1/2 cups sugar and cornstarch; stir into berry mixture. Cook and stir until thickened and bubbly.
Spread berry mixture over partially baked crust. Bake for 25 minutes. Cool on wire rack. Remove side of pan. Place tart on serving platter, and drizzle with melted white baking bar. Sprinkle with chopped hazelnuts, if desired. Makes 10 servings.