Preheat the oven to 400 degrees, and cover a baking sheet with parchment paper.
Sift together the flour, baking powder, sugar, and salt into a large mixing bowl.
Using a pastry cutter, cut the butter into the flour mixture, until it all resembles small peas.
In a small bowl, mix together the yolks, milk, cream, vanilla, and orange zest. Stir it into the flour mixture just until no streaks of flour are left. Stir in the cranberries and white chocolate chips.
Dump the mixture onto a floured board, and pat it into a one inch thick circle. Using a floured knife, cut it into eight wedges. Place them on the baking sheet, spaced two inches apart.
Brush each wedge lightly with some heavy cream and sprinkle with coarse sugar. Bake them for twenty minutes, or until they're light brown.
Make the glaze by combining all the ingredients. Use a piping bag to apply the glaze to the scones. Serve warm.