Preheat the oven to 350F. Grease and flour two 9" cake rounds (or three 8" cake rounds).
In a medium bowl whisk together flour, baking powder, baking soda, cinnamon, nutmeg, cloves and salt. Put to the side.
In an electric mixer, beat the butter until smooth. Add the sugar then beat on medium-high speed until light and fluffy. This may take 2-3 minutes.
Reduce the speed and add the eggs one at a time, fully incorporating before adding the next egg. Add oil ad vanilla and mix until well combined.
Alternate adding dry ingredients (that we set aside earlier) and the pumpkin puree, beginning and ending with the flour. (This should be three additions of flour and two additions of pumpkin puree). Mix until just combined.
Spread the batter evenly into the prepared pans and smooth out the tops of each cake.
Bake for 20-25 minutes or until a toothpick inserted into the center comes out clean.
Place cake on wire racks to cool for 10 minutes then turn the cake onto wire rack to cool completely.
Beat butter and shortening until smooth. Slowly add 6 cups of powdered sugar, fully incorporating after each addition. Add the maple extract (or syrup), cinnamon and water or milk and mix until smooth. Add remaining powdered sugar 1 cup at a time. Mix thoroughly until smooth.
Preheat oven to 350F. and line baking sheet with parchment paper.
In medium bowl, combine all ingredients with a fork until combined and crumbly. Spread evenly on baking sheet and bake for 6-8 minutes. Cool completely and crumble into pieces if needed.
Trim off the curved dome on the top of the cakes in order to allow the two cakes rounds to be stacked on top of each other. Place one of the rounds on a serving plate or cake stand. Top the bottom cake round with 3/4 cup of frosting and spread evenly. Sprinkle the frosting with 1/2- 3/4 of the streusel. Lightly press the streusel into the frosting. Place the second cake round on top of the first cake round and top with frosting. The frosting should go on top of the second cake round as well as on all sides of the cake. Sprinkle with remaining streusel.
Store at room temperature in an airtight container. Best eaten within 2-3 days.