In a shallow pan over medium heat, toast the oats, butter and light brown sugar for 5 minutes until fragrant and golden brown. Set aside to cool reserving about 2 TBSP for garnish.

Whip the room temperature mascarpone and cream until soft peaks form. Add in Liqueur ( Grand Mariner or whiskey) and whip for 30 seconds more.

Fold in cooled oats and gently fold raspberries into the cream mixture. Spoon into champagne coupes, sprinkle with a few more toasted oats, sliced berries and mint leaves. Chill overnight if desired.