How to Make It
Make the coconut jam: Add sugar and coconut water to a small saucepan. Bring to a boil, and then stir in coconut and vanilla. Set aside and allow to cool.
Make the pastry dough: Preheat oven to 350° F. Sift flour and salt into food processor. Slowly add butter. Pulse until mixture resembles course sand. Slowly add ice water and continue pulsing until mixture combines. Chill in refrigerator for an hour. Roll chilled pastry dough over floured surface. Cut circles out of the dough and place into eight 4 ½-5 inch buttered pastry pans. Prick bottom of dough with a fork. Place pie weights over the dough to prevent it from puffing up, then bake for 15 minutes or until golden-brown.
Make the sponge cake: Mix eggs and sugar on high speed for 8 minutes. Reduce to medium speed and mix for another 8 minutes. Add lime zest and stir well. Fold in flour, then add butter and vanilla.
Spread thick layer of coconut jam over the bottom of each golden-brown tart shell. Spoon cake batter over the jam in a thick layer, leaving about ¼ inch from the top of the pan (as the cake will puff up). Bake for 25 minutes or until the top of the cake is golden-brown.