In a medium bowl, macerate the berries with the sugar, balsamic, & lemon zest for 30 minutes.
Prepare the whipped cream by hand - Place 2" of ice in the bottom of a large bowl. Fill until just covered with cold water. Place a medium bowl on the ice with heavy cream & confectioner’s sugar. Begin whipping with a balloon whisk & add in the Basil Olive Oil slowly. Whip until soft peaks are formed & the cream is smooth. With a stand mixer: Whisk the heavy cream & sugar together; slowly drizzle in the oil. Whisk until soft peaks are formed & the cream is smooth. Watch the cream as this happens quickly!
Place the berries over the cake with the sauce that it forms. Dollop cream on top & garnish with a basil leaf if so desired.