Pre-heat the oven to 350 degrees and line a baking sheet with parchment paper. Beat butter and sugar until light and fluffy, about 4 minutes. Add corn flour, egg, vanilla extract, cinnamon; mix well. Slowly add the milk mixing just until dough comes together. Shape the dough into 1 ¼ inch balls and place 3 inches apart on baking sheet. Flatten each cookie in a crisscross patter with a fork. Bake for 10-13 minutes or until bottom of cookie is light and golden brown. Remove the cookies from the oven, allow to cool on baking sheet for a few minutes, and then transfer to a rack to cool completely. Warm dulce de lehce in the microwave, drizzle cookies with warm dulce de lehce.