Pulse pineapple in the food processor until it has nearly the same texture as the grated coconut.
Mix pineapple and coconut. Mix in sugar, 1 tablespoon of flour, salt and cinnamon powder.
For the cups
Heat oven to 400 ºF [200 ºC].
Thaw the puff pastry sheet in the refrigerator until they are pliable.
Sprinkle flour on the clean counter and roll out using a rolling pin. Sheet should be about ⅛-inch [0.25 cm] thick.
Cut circles with a 3” [7.25 cm] cookie cutter.
Place the circles in mini-muffin molds and paint with the yolk.
Fill each with 1 tablespoon of the filling.
Bake for 20 minutes, or until cups are golden brown.
In the meantime, whisk the egg whites with the wire attachment over high speed. When it forms peaks sift in sugar and cornstarch and whisk until it forms stiff peaks (2-3 mins).
Pipe meringue on each mini-tart and return to the oven with overhead heat until the meringue is crisp and slightly browned.