In a medium bowl, combine 1 cup flour and the 3 tablespoons granulated sugar. Cut in the 1/3 cup butter until mixture resembles fine crumbs and starts to cling. Pat into the bottom of a 9x9x2-inch baking pan.
For filling, in the medium bowl, beat the 1-1/4 cups granulated sugar and the 3/4 cup butter until combined. Beat in the corn syrup and egg just until combined.
Add 1 cup flour and evaporated milk alternately to beaten mixture, beating until just combined (batter will appear slightly curdled).
Pour into crust-lined baking pan. Bake in a 350 degree F oven about 35 minutes or until the cake is nearly firm when you shake it. Cool in pan on wire rack. Remove to serving plate. Sprinkle with powdered sugar, if you like. Makes 9 servings.