Preheat the oven to 180°C (350°F) and line a baking sheet with parchment paper.

Cream the butter and brown sugar together until light and fluffy.

Add the egg yolk and mix until fully incorporated.

Sift in the flour, cocoa powder, baking powder, and salt, then mix until a soft dough forms.

Divide the dough into small portions and flatten each portion in your palm.

Place a piece of caramel candy in the center and wrap the dough around it, sealing it completely.

Arrange the filled dough balls on the baking sheet, spacing them slightly apart.

Bake for 10-12 minutes or until the edges are set.

Let the cookies cool on the baking sheet for 5 minutes, then sprinkle with sea salt flakes before transferring to a wire rack.