In a bowl, combine ¼ cup of the sugar and the flour, then cut in the cold butter, gently incorporating the ingredients until the texture resembles coarse crumbs. Press the crust into an ungreased 13x9-inch baking pan.
Preheat the oven to 425°F. In a bowl, combine the eggs, pumpkin, salt, cinnamon, ginger, cloves and the remaining sugar. Stir in the milk until the mixture becomes smooth, then pour the filling over the crust.
Bake the pumpkin shortbread bars at 425° for 15 minutes. Reduce the heat to 350°, and bake for an additional 50 to 55 minutes or until the filling is set.
Let the dessert cool in the pan, on a wire rack. Then cover and refrigerate it overnight.
When you're ready to enjoy the dessert, cut it into 15 squares. Serve the bars with whipped cream and additional cinnamon sprinkled on top, if desired.
