In a large mixing bowl, pour in the heavy whipping cream and beat on medium speed until soft peaks form, about 2-3 minutes. Set aside.

Gently fold in the mascarpone cheese, powdered sugar, and vanilla extract. Mix until you achieve stiff peaks, around 2 minutes.

Arrange the ladyfingers in a single layer in a 9x13 baking dish. Brush half with orange juice and let soak briefly.

Spread half of the mascarpone mixture over the ladyfingers, then layer sliced bananas on top.

Repeat with another layer of ladyfingers, brushing with remaining orange juice, followed by the rest of the mascarpone mixture and more banana slices.

Spread Cool Whip over the top, creating a smooth surface.

Cover with plastic wrap and refrigerate for at least 4 hours, or overnight, to allow flavors to meld.

Garnish with fresh banana slices just before serving and slice into squares.