Put the pie crust in the bottom of 9-inch pie plate lined with parchment paper.
Put the pecans in the pie crust.
Combine the rest of the ingredients in a blender. Blend until smooth. Pour the mixture into the pie shell over the pecans.
Bake until the filling is set about 35-40 minutes. Let cool completely.
Pumpkin Pie Layer
Put the pie crust in the bottom of 9-inch pie plate lined with parchment paper.
Combine the ingredients in a blender. Blend until smooth. Pour the filling into the crust.
Bake on the bottom rack until the filling is set about 45-50 minutes. Let cool completely.
Spice Cake Layer
This will make 2 cakes. You only need one for the piecaken. You can half the ingredients to just bake one if you prefer.
Line two 9-inch cake pan with parchment paper.
Prepare batter as directed on box.
Add to prepared pans.
Bake as directed. Let cool completely.
Apple Pie Filling
While the pies and cake are baking put the apples and sugar in a frying pan. Cook over low until softened.
Stir in the flour. Cook until the juices thicken. Stir in the lemon juice and cinnamon. Let cool completely.
Cinnamon Buttercream
Cream the butter and cream cheese until smooth. Gradually add the sugar.
Add the cinnamon, one tablespoon of milk, and vanilla. Mix until smooth.
Add more milk, if needed, to reach a pipeable consistency.
Assembly
It is best to make the pies, cake, and apple filling the day before. Chill in the refrigerator overnight for best results.
Transfer the pies and cake to a large cutting board.
Use the 8-inch cake ring to cut an 8-inch circle in each layer.
Gently place the pecan pie in the bottom of the cake ring. Top with a thin layer of buttercream.
Next, place the pumpkin pie in the cake ring. Top with a thin layer of icing.
Finally, place the spice cake in the cake ring. (If possible, pause here and refrigerate the piecaken for one hour to set the layers).
Remove the cake ring. Cover with a thin layer of frosting.
Put the apple filling in the center of the top of the cake. Pipe rosettes around the filling and along the bottom edge.
Refrigerate until ready to serve. Once the frosting has hardened you can wrap in plastic wrap.
If making ahead of time I recommend adding a few long wooden skewers so the layers don't shift. Remove them right before serving. The apple filling will hide the holes.