Preheat oven to 350°F. Grease a 9x13 baking pan with cooking spray.
In a large mixing bowl, combine cake mix, sugar, oil, eggs, pumpkin puree, pumpkin pie spice and vanilla. Beat with an electric mixer until smooth and combined. Pour batter into the prepared pan, smooth the top, and bake for 38-40 minutes, or until a toothpick comes out clean.
Let the cake cool for at least 30 minutes, then poke holes all over the cake with a bamboo skewer.
In a large bowl, combine evaporated milk, sweetened condensed milk, and half and half. Slowly pour over the cake, making sure to get in all the holes.
Top cake with plastic wrap and refrigerate for at least 3 hours.
Before serving, make the whipped topping. In a large bowl, whip cream with sugar and vanilla with an electric mixer or a stand mixer. Mix until soft peaks form, then spoon and spread over the cake. Sprinkle with pumpkin spice or cinnamon before serving.