Preheat oven to 325 degrees. Grease 2 cookie sheets. Place the butter and superfine sugar in a bowl and beat until light and fluffy. Sift the flour, cornstarch, and cinnamon into a separate bowl, then gradually work dry ingredients into creamed mixture with a wooden spoon. When well mixed, knead until smooth.
Take 1 teaspoons at a time of the mixture and roll into a ball. place the balls on the prepared cookie sheets. Bake in a preheated oven for 30-40 minutes, or until pale golden.
Place the confectioners' sugar in a shallow dish and toss the pastelitos in it while they are still warm. Let cool on cooling racks.