Preheat your oven to 350°F. Line two baking sheets with parchment paper.

Cream the softened butter and sugar together in a large bowl until light and fluffy. Add the egg yolk and vanilla extract, then mix until combined.

Add the flour and salt to the butter mixture. Stir gently until just combined. Fold in the shredded coconut.

Roll the dough into balls about 1 tablespoon each and place them on the prepared baking sheets, spacing them about 2 inches apart. Press your thumb into each ball to create a deep indentation.

Fill each indentation with about 1/2 teaspoon of jam.

Bake for 12-15 minutes until the edges turn golden brown. Let them cool on the baking sheet for 5 minutes before transferring to a wire rack.