Preheat the oven to 450 degrees F (230 degrees C). Roll pizza dough out on a lightly floured surface. Transfer to greased 12-inch (30 cm) round pizza pan. Brush butter over dough. Combine sugar with cinnamon and sprinkle evenly over pizza.
Bake for 15 to 18 minutes or until golden and puffed. Cool for 15 minutes.
Meanwhile, pipe enough whipped cream into a measuring cup to measure 2 1/2 cups (625 mL); stir into sour cream until smooth. Stir in vanilla. Spread cream mixture over pizza base and top with bananas and strawberries.
Warm hazelnut spread in the microwave on High for 30 seconds or until pourable. Drizzle spread over the fruit. Cut into wedges and serve immediately with additional whipped cream (if desired).