Chill a large mixing bowl and beaters in the freezer for 10–15 minutes to help the cream whip faster. Soak the gelatin sheets in a bowl of cold water until soft for about 5–10 minutes.

Whip the heavy cream and mascarpone in the very cold bowl, adding the powdered sugar gradually until soft peaks form.

Warm the coconut milk in a small saucepan until warm. Remove from heat, squeeze excess water from the soaked gelatin sheets, and stir them into the warm coconut milk until fully dissolved.

Allow the coconut milk mixture to cool slightly, then gently fold it into the whipped cream using a spatula until homogeneous and airy.

Spoon or pipe the mousse into hemisphere molds adding a teaspoon of cocoa spread in the center of each dome then cover with more mousse. Smooth the surface and place molds in the freezer for at least 6 hours.

Preheat oven to 180°C (350°F). Cream the softened butter with powdered sugar until smooth. Add egg yolks and mix, then sift in flour, cocoa powder, sea salt, and baking powder.

Mix until you get a cohesive dough, then chill in the refrigerator for 30 minutes to firm up.

Roll out the dough to about 1 inch thickness, cut out circles, and bake for about 10 minutes. Let cool completely on a rack.

Remove frozen mousse domes from molds and place on cooled Cocoa Breton shortbread bases.

Let the domes thaw at room temperature for about 2 hours before serving. Sprinkle grated coconut over each dome.