In a mixing bowl, stir together the flour, 1/2 cup of the sugar, vanilla, and egg yolks until everything looks evenly combined. Add the softened butter and work it in with your fingertips or a pastry cutter until the mixture comes together. Shape it into a ball and place it in the refrigerator to chill for about an hour.

While the dough chills, pulse the cranberries in a food processor until finely chopped. Add them to a saucepan with the diced apple, orange juice, orange zest, the remaining sugar, cornstarch, ginger, and salt. Warm the mixture over low heat, stirring often, until it thickens and becomes jammy. This takes about 15 minutes. Remove from the heat and stir in the chopped walnuts. Let the filling cool.

When you are ready to bake, heat the oven to 375 degrees F. Press about two-thirds of the chilled dough into the bottom of a 9x13 pan to form an even layer. Spread the cooled cranberry apple filling over the top.

Roll out the remaining dough on a lightly floured surface until it is about 1/4 inch thick. Cut it into thin strips with a knife or pastry wheel, then lay the strips over the filling in a simple crisscross or lattice pattern. Place the pan in the oven and bake for about 20 minutes, or until the top looks lightly golden.

Let the bars cool completely in the pan, then slice them into squares or slender rectangles.