In a large bowl, mix together the butter, vanilla and confectioners' sugar until smooth. Sift together the flour and corn starch. Add the flour mixture to the bowl and stir by hand until a dough forms.
Roll dough into 1 inch balls and press into miniature muffin cups. Mold dough into the shape of the cup. (it's much easier if you use a tart shaper. If you do use this, make sure to flour it every 1-2 tarts, otherwise it will stick.).
In each cup, put 1 teaspoon of pineapple preserves.
In a small bowl, Mix sugar and egg until well blended. Stir in the flaked coconut and put 1 teaspoonful of the coconut mixture onto each of the pineapple filled tarts.
Bake in the preheated oven for 25 to 30 minutes. Cookie crusts should be slightly golden.
Cool tarts in the pan for at least 15 minutes before attempting to remove. (They may be very diffucult to remove from the pan. If they are, it's easiest to cut off the top and take the bottom out, then put them back together and no one will notice!)
Lightly tap mini muffin pans on the counter to loosen tarts. Dust lightly with confectioners' sugar before serving.