Whip the mascarpone and vanilla paste in a medium-sized bowl for 60 seconds (I use a hand mixer).
Add the heavy cream and whip only until soft peaks form.
Fold in the maple syrup.
Melt the dark chocolate.
Add 50 grams of the melted dark chocolate to a piping bag, and let the remaining chocolate cool until lukewarm.
Trace the outline of the serving glasses on parchment paper (turn the paper over).
Pipe a dark chocolate flower on top of the outline, making sure it is wider than the glass.
Repeat, and allow the flowers to set.
Fold the cooled 150 grams of dark chocolate into the mascarpone cream.
Whip the heavy cream for the topping.
Divide the mousse into serving glasses, and top with whipped cream and chocolate flowers.