Begin by melting the dark chocolate and coconut oil together in a microwave-safe bowl. Heat in 30-second increments, stirring in between, until smooth and glossy.

With the melted chocolate, generously coat the interiors of silicone dome molds. Freeze for approximately 15 minutes or until the chocolate has hardened.

In a small bowl, sprinkle the gelatin powder over the water and let it bloom for about 5 minutes. Microwave briefly until warm and fully dissolved.

In a large mixing bowl, whip the heavy cream and granulated sugar together until soft peaks form.

Mix a small portion of the whipped cream with the matcha powder in a separate bowl to create a smooth paste. Fold this back into the remaining whipped cream.

Carefully fold the cooled gelatin and vanilla extract into the matcha mousse mixture, ensuring everything is incorporated without deflating.

Spoon the matcha mousse mixture into the chilled chocolate-coated molds. Smooth the tops and cover with plastic wrap. Freeze for at least 2 hours.

After freezing, carefully remove the mousse domes from the silicone molds. If difficult, warm the molds gently for easy release.

Dust the tops lightly with matcha powder for an appealing finish and serve on dessert plates with berries or edible flowers.