1In a large bowl, cream together the butter and sugar. Add the milk and coconut extract; continue to cream until light and fluffy. Sift together the flour, baking powder, and salt; stir this into the creamed mixture with a wooden spoon, then stir in the coconut. The dough will seem crumbly, you may need to use your hands to help it come together. Divide the dough into 4 equal parts and roll into 10 inch long logs. Wrap logs in plastic or wax paper and refrigerate for at least 1 hour.
2Preheat oven to 325 degrees F ( 165 degrees C ).
3Cut each log into 1/2 inch slices with a serrated knife. Place the cookies 1 inch apart on a cookie sheet. Using a toothpick or pencil, make 4 holes in each cookie to resemble a button. Bake in the preheated oven for 20 to 25 minutes. Allow cookies to cool on wire racks. When the cookies are cool, melt the shortening and semi sweet chocolate together in a microwave or over a double boiler; mix well. Dip the cookies halfway into the chocolate and scrape off the excess with a spatula or your finger. Place them on wax paper to set.