In a bowl, combine sliced strawberries, sugar, and vanilla extract. Gently toss the strawberries until they are coated in sugar and vanilla. Let them sit for about 15 minutes to allow the flavors to meld.
In a separate mixing bowl, whip the heavy whipping cream until soft peaks form. Add powdered sugar to the whipped cream and continue whipping until stiff peaks form. Be careful not to over-whip.
In serving glasses or bowls, begin layering the parfait. Start with a spoonful of whipped cream at the bottom. Add a layer of the macerated strawberries on top of the whipped cream.
Sprinkle a layer of granola over the strawberries. Repeat the layers until you reach the top of the glass, finishing with a dollop of whipped cream.
Garnish the top with a fresh strawberry slice and a sprig of mint leaves if desired. Chill the parfaits in the refrigerator for at least 30 minutes before serving to allow the flavors to meld and the parfait to set.
Serve the Strawberry Parfait with Whipped Cream chilled and enjoy this delightful and refreshing dessert!