Add the oil, vinegar and vanilla and stir. Mixture will be lumpy.
Pour in the hot water and stir until the lumps are gone.
For the pumpkin cake
Cream together the butter and sugar until fluffy.
Beat in the eggs one at a time, being sure to scrape down the edges after adding each egg. Beat in the vanilla.
Add 1 cup of the flour along with the baking soda, baking powder, salt, and pumpkin spice. Mix well. Add 1/4 cup of milk and stir. Then add the remaining cup of flour and stir.
Gently fold in the pumpkin puree.
For the frosting
Beat the cream cheese and butter together with a stand or hand mixer. Add the vanilla and beat again.
Add the cocoa powder, cinnamon, and 1 cup of powdered sugar. Beat slowly until the sugar is well-incorporated.
Add the rest of the sugar in increments, beating well after each addition.
Slowly add the milk a tablespoon at a time until desired consistency is reached.
To prepare the cakes
Grease 4 round cake pans on the sides and bottom. Then line the bottom with a circle of parchment paper and grease again.
Add equal amounts of chocolate and pumpkin cake batter to the pans, alternating the chocolate and pumpkin batter. Gently swirl with a knife if desired.
Bake in a 350-degree oven for 35-40 minutes or until a toothpick inserted in the middle comes out clean.
Let cakes cool completely. Then remove from the pans and take the parchment paper off the bottom.
Level the cakes if desired. Stack the layers on top of one another with a generous amount of frosting between each layer.