In a large bowl, combine the berries with granulated sugar and toss gently. Let them sit for 10 minutes to release their juices and create a light syrup.
While berries macerate, beat the heavy cream with powdered sugar and vanilla extract using a hand mixer on medium-high speed until stiff peaks form, about 3-4 minutes. Fold in the sour cream or mascarpone until smooth and combined.
In a small bowl, toss the crushed cookies with melted butter until the crumbs are evenly coated and slightly clumpy.
To assemble, spoon 2-3 tablespoons of cookie crumbs into the bottom of each clear cup or jar. Press down gently to create a base layer.
Add a layer of vanilla cream (about 1/4 cup per cup), spreading it gently to the edges without disturbing the cookie layer below.
Spoon a generous layer of macerated berries with some of their juices over the cream, then repeat the layering process one more time: cream, then berries.
Top each parfait with a final sprinkle of cookie crumbs and a few whole berries. Garnish with a mint leaf if desired.
Cover and refrigerate for at least 30 minutes to let flavors meld, or up to 8 hours. Serve chilled with long spoons.