Preheat oven to 425 degrees
Mix flour, baking powder, and salt in a large bowl
Chop butter into mixture with a pastry cutter or knead in with your fingers until you get a sandy mixture
Add sugar and mix
Add milk and lemon extract and stir with a fork until dough forms
Roll the dough out about ½ inch thick
Cut out 3 inch squares and transfer to a cookie sheet
Criss-cross each square from corner to corner with a knife
Bake for about 12 minutes or until set and lightly golden
Makes 10 to 12