Combine flour, 1/4 cup sugar, and cold butter. Grind everything into crumbs, press into a 13 * 9-inch baking dish.
In a deep bowl, combine the remaining sugar, pumpkin, salt, spices, eggs, and combine. Pour in evaporated milk, stir until smooth, pour over a layer of dough.
Bake in preheated to 425 F oven for about 50 minutes, or until filling settles. Cool on a wire rack, then refrigerate overnight. Cut into portions, garnish with whipped cream, sprinkle with ground cinnamon.