Preheat oven to 350 degrees
Beat 1 1/2 cups of sugar, butter and vanilla in mixer at medium speed until well blended.
Add pumpkin puree and eggs (one at a time) and beat until combined.
In small bowl, whisk together flour, baking powder and salt.
Add flour mixture to sugar mixture and beat at low speed until well blended.
Combine remaining 1/4 cup sugar and cinnamon in small bowl.
Toss the chopped and peeled apples with 2 Tbsp if the cinnamon sugar.
Fold apples into cake batter and gently combine.
Pour batter into an 8 inch springform pan that is coated with cooking spray.
Lightly sprinkle the rest of the cinnamon sugar on top of the batter.
Bake at 350 degrees for 1 hour and 10 minutes or until cake slightly browns on top (I like to check it at 1 hour with a cake tester).
Cool on wire rack, then carefully remove spring form pan and serve.