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

Add the mascarpone cheese, powdered sugar, and vanilla extract to the whipped cream. Continue mixing until thickened, about 2-3 minutes.

Line a 9x13 baking dish with ladyfingers in a single layer.

Brush half of the ladyfingers with half of the orange juice, ensuring they are moist but not soggy.

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

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

Spread Cool Whip over the top of the assembled tiramisu.

Cover and refrigerate for at least 4 hours, or overnight.