For the Cake Batter

1. Pre-heat oven to 350°F
2. In a large mixing bowl combine, softened butter and sugar, then mix well.
3. Add the egg, vanilla and pumpkin then mix until just combined.
4. Sift together flour, baking powder and salt and set aside.
5. Alternate adding the buttermilk and flour mixture, starting and ending with the flour then set batter aside.

For the Filling

1. In a small bowl combine the filling ingredients and mix together with a fork until melted butter is evenly distributed and set aside.

For the Topping

1. In a small bowl combine the filling ingredients and mix together with a fork until melted butter is evenly distributed.  Mixture will start to clump together.

Assembly

1. Grease (or use parchment paper as a liner) a 9×9 baking pan and put half of the batter into the bottom of the pan and spread it evenly to the edges of the pan.
2. Evenly sprinkle the filling ingredients over the bottom layer of the batter, use ALL of the filling, it seems like a lot but it works out perfect.
3. Add the remaining batter over the filling layer by taking scoops of batter then spreading it.  Batter is thick so it can be difficult to spread if you just put it in the center a spread it out (if that makes sense).
4. Add ALL of the streusel topping on top and evenly distribute it.
5. Place in the oven for 45-50 minutes or until inserted toothpick comes out clean, do NOT over bake.
6. Remove from oven and allow to cool for 5-10 minutes before serving and ENJOY every bite!