Preheat your oven to 350°F (175°C). In a large mixing bowl, beat softened cream cheese until smooth and fluffy. Gradually add granulated sugar, all-purpose flour, vanilla extract, ground cinnamon, and heavy whipping cream, blending until well combined. Incorporate the eggs one by one, mixing until just blended. Pour the mixture into a greased springform pan and bake for 10 minutes, then reduce the oven temperature to 200°F (93°C) and bake for another 30-35 minutes until slightly jiggly. Cool, then refrigerate overnight.

Prepare your baking pan by greasing and lining it with parchment paper. In a medium bowl, mix together the flour, baking powder, and ground spices. In a separate large bowl, beat softened butter and brown sugar until creamy, then add vegetable oil, eggs, and vanilla extract, mixing until smooth. Gradually combine the dry ingredients with the wet, alternating with milk until just mixed. Pour the batter into the prepared pan and bake at 350°F (175°C) for 15-17 minutes, or until a toothpick inserted comes out clean. Let it cool, then wrap and refrigerate overnight.

In a clean mixing bowl, beat unsalted butter on medium speed until fluffy and pale. Gradually add powdered sugar, mixing until combined. For a hint of warmth, mix in ground cinnamon, then blend in vanilla extract and heavy whipping cream until your frosting achieves a light, spreadable consistency. If it's too thick, add a splash of cream until right. Keep the frosting covered until you are ready to assemble your Thanksgiving Piecaken.

Once all layers are fully cooled, start by trimming the edges of the cheesecake and spice cake to ensure evenness. On a sturdy serving plate or cake stand, stack the cheesecake layer, followed by the spice cake layer, and top with a chilled store-bought pumpkin pie. Use the buttercream frosting to fill the gaps between layers and generously frost the top and sides of the entire piecaken. Chill the assembled piecaken for 20-30 minutes to set, then smooth out the final layer of frosting and embellish as desired with a sprinkle of cinnamon before slicing and serving.