Place the butter and sugar in a large bowl and beat on medium speed for almost 3 minutes until it is soft with a hand-held mixer or with paddle attachment if using a stand-mixer. Scrape the sides with a spatula during this and other steps so everything is combined well.
Add the egg and mix well. Then add the flour and mix until combined. Finally add the coconuts and mix until all incorporated.
Divide the dough in half. Flatten and put them into freezer bags or wrap with plastic film and keep in the refrigerator for 30 minutes to rest.
Preheat the oven to 350°F(177C°). Line baking sheet with parchment paper or silicone baking mat.
Take the doughs from the fridge. Lightly flour the work surface, rolling pin and the dough. Roll out the doughs into approximately 6*10 inch (16*25cm) long rectangle, ⅙ inch (4cm) thick. Using a heart cookie cutter that is 1.77inch(4,5cm) big, cut out and place them on the baking sheet covered with parchment paper. Form the leftover dough into a ball and repeat the steps (roll out and cut out the dough) until no dough remains.
Bake for 8 minutes or until the edges get golden brown and top of them start to change color. Remove the cookies from the oven. While the cookies are cooling, melt the chocolate over bain marie: place the chopped chocolate into a heatproof bowl that sits over a pan of simmering water. Stir often. Dip half of the cookies into the melted chocolate and dripp off the excess. Place them on a baking sheet covered with parchment paper. Keep the cookies in the fridge for almost 10 minutes to let the chocolate set.