Preheat oven to 325 degrees F. Line a 13x9x2-inch baking pan with parchment paper; set aside.
In a large bowl stir together the flour, granulated sugar and salt. Coarsely shred the butter over the flour mixture. Toss in with a fork. Use your fingers to gently massage the butter into the flour until the mixture resembles coarse cornmeal and the mixture sticks together when squeezed between your fingers.
Add the nuts, baking pieces, and cranberries and stir lightly to mix. Transfer to the prepared baking pan and press evenly. Sprinkle the top with coarse sugar. Bake for 60 to 70 minutes or until top is golden brown. Remove and cool in pan on a wire rack for at least 2 hours.
Remove from pan and cut into bars. Cover and store shortbread in the refrigerator for up to 3 days (or in the freezer for 3 months).
In a large saucepan combine the grapefruit juice, cranberry juice, 3 cups sugar, vanilla bean, cinnamon, zest, and salt. Cook and stir over medium heat until sugar has dissolved. Remove and allow to cool until warm but not hot, about minutes.
Add the cranberries to the mixture and stir. Let stand until room temperature. Transfer to a bowl; cover and chill overnight.
Drain cranberries well, reserving syrup and vanilla bean. Cover and chill the syrup with the vanilla bean for up to 3 weeks. Remove 1/2 (about 2 cups) of the cranberries. Toss with 1/4 cup red decorating sugar. Toss remaining cranberries with the 1/4 cup white sugar.
Spread the cranberries out in a parchment paper-lined shallow baking pan, keeping the colors separate. Let stand for 1 hour to dry. Store loosely covered at room temperature for up to 1 week.