Roll pastry to fit a 12 inch pizza pan; fold under the edges. Combine sugar, flour and cinnamon in a medium bowl. Add apples and toss. Arrange the apples in a single layer over the pie crust to completely cover it.
Combine the first 5 topping ingredients in a bowl and then sprinkle evenly over the apples.
Bake at 350 degrees F for 35 to 40 minutes or until apples are tender. Remove from oven and immediately drizzle with caramel topping. Let stand 10 minutes.
Cut into pizza slices and serve warm with vanilla ice cream!