In a food processor or bowl, mix flour, cornstarch, sugar, and baking powder.
Add butter; whirl or rub with your fingers to form fine crumbs.
Stir in almonds, coconut, and chocolate.
Then add milk and stir until mixture is moistened.
With floured hands, roll dough into 1 1/2-inch balls.
Place balls 2 inches apart on ungreased 12- by 15-inch baking sheets.
Press each ball to 3/8-inch thick.
Bake in a 300° oven until cookies are a rich golden brown, about 35 minutes.
If using 1 oven, alternate pan positions after 15 minutes.