Preheat oven to 350 degrees. Lightly coat a 9x13 pan with non stick cooking spray and line with parchment paper. In bowl whisk together flour, baking powder, baking soda and ground cinnamon. In a large bowl using an electric mixer beat pumpkin (or oil) and sugar until well blended. Add eggs one at a time, beating well after each addition. Add vanilla, pumpkin and beat until combined. Reduce speed and slowly add dry ingredients, mix until combined. Stir in pineapple and pour batter into baking pan. Bake 30-35 minutes or until toothpick inserted comes out clean. Whisk together the sweetened condensed milk, evaporated milk and milk in a small bowl. When cake is done, remove from oven and allow to cool for 10 minutes. Carefully remove cake from pan, using parchment paper and place in serving platter. Poke the top of cake with holes and slowly pour milk over entire cake. Refrigerate cake overnight. Whisk heavy cream, sugar and vanilla until soft peaks form. Top cake with freshly whipped cream and garnish with diced pineapple.