Preheat your oven to 350°F (175°C).

In a medium bowl, whisk together the all-purpose flour, shredded coconut, baking powder, and salt. Set aside. In a large bowl, cream the softened butter and granulated sugar together until light and fluffy, about 2-3 minutes. Add the egg yolk and vanilla extract, mixing until well combined. Gradually add the dry ingredients to the wet mixture, stirring gently until just combined. Fold in the crushed pineapple.

Scoop out the dough and roll it into balls, about 1 inch in diameter. Place on a baking sheet, leaving about 2 inches of space between each.

Using your thumb or the back of a spoon, press down in the center of each dough ball to create an indentation.

Fill each indentation with a small dollop of pineapple preserves.

Bake for 12-15 minutes until edges are lightly golden. Let cool on the baking sheet for about 5 minutes before transferring to a wire rack. Dust with powdered sugar before serving.