Preheat your oven to 350°F (175°C) and grease a springform pan. In a large mixing bowl, beat softened cream cheese until super smooth. Gradually add in granulated sugar and all-purpose flour, mixing in vanilla extract and ground cinnamon. Incorporate heavy whipping cream and large eggs until fully combined. Pour mixture into the prepared pan and bake for 10 minutes, then lower temperature to 200°F and continue baking for 30-35 minutes. Cool in the oven with the door ajar for 15 minutes before refrigerating overnight.

Once the cheesecake has cooled overnight, preheat oven again to 350°F (175°C) and prepare a separate cake pan. Mix dry ingredients in a bowl. In another bowl, cream unsalted butter and brown sugar until fluffy, about 3-4 minutes. Mix in egg, vegetable oil, and vanilla extract until blended. Combine the flour mixture with milk, stirring until smooth. Pour batter into the prepared pan and bake for 15-17 minutes, or until a toothpick comes out clean. Cool and refrigerate overnight.

In a mixing bowl, cream softened unsalted butter for the frosting until smooth. Gradually add powdered sugar and mix in vanilla extract and heavy cream or milk, beating until fluffy. Trim edges of cheesecake and spice cake for neat stacking. Place cheesecake layer on a serving plate, spread frosting over it, and top with spice cake. Frost the top again and carefully place the pumpkin pie on top. Frost the entire dessert generously and chill for 20-30 minutes to set the frosting.

Before serving, optionally garnish the top with a sprinkle of cinnamon. Slice generous pieces and serve this decadent dessert.