Preheat oven to 375 degrees F (190 degrees C). Grease two 24-count mini-muffin tins with cooking spray.
Cut each puff pastry sheet into quarters. Cut each quarter into 4 square pieces. Fill each mini-muffin cup with 1 puff pastry square.
Spread 1 teaspoon chocolate-hazelnut spread over each pastry square. Place 3 banana slices on top.
Bake in the preheated oven until golden brown, 15 to 18 minutes.. Transfer to a wire rack to cool completely.
Beat cream cheese in a bowl with an electric mixer until smooth, about 2 minutes. Add heavy cream, sugar, and vanilla extract; beat until frosting is thick and creamy.
Pipe or spoon cream cheese frosting on over banana slices.
