In a large chilled bowl, combine heavy cream, powdered sugar, and vanilla extract. Beat with an electric mixer on medium-high speed until soft peaks form, about 2-3 minutes. Do not overwhip.
Add mascarpone cheese to the whipped cream and gently fold together with a spatula until smooth and fully incorporated, being careful not to deflate the mixture.
In a separate bowl, toss the strawberries, blueberries, and raspberries with granulated sugar and lemon juice. Let sit for 5 minutes to release juices slightly.
Crush the vanilla wafers in a sealed plastic bag using a rolling pin until you have coarse crumbs with some larger pieces remaining for texture.
To assemble, spoon 2-3 tablespoons of cream mixture into the bottom of each parfait glass or jar. Tap gently on the counter to settle.
Add a layer of mixed berries, then sprinkle with cookie crumbs. Repeat layering process two more times, ending with a cream layer on top.
Garnish each parfait with a few whole berries arranged to resemble flower petals and a small mint leaf in the center.
Refrigerate for at least 30 minutes before serving to allow flavors to meld and layers to set slightly. Serve cold within 4 hours for best texture.
