1. Prepare the Crust:

1. Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.
2. In a bowl, whisk together flour and 1/2 cup shredded coconut. Set aside.
3. In another bowl, cream together butter, granulated sugar, and brown sugar until light and fluffy. Add egg yolk and vanilla extract, mixing well.
4. Gradually add the dry ingredients to the wet mixture, mixing until a dough forms.
5. Roll dough into 1-inch balls and place on the prepared baking sheet. Use your thumb or the back of a spoon to make an indentation in the center of each cookie.
6. Fill each indentation with about 1/2 teaspoon of pineapple jam.
7. Bake for 12-15 minutes, or until the edges are lightly golden.
8. Remove from oven and sprinkle with remaining shredded coconut while still warm. Let cool on the baking sheet for 5 minutes before transferring to a wire rack.