In a bowl, combine pumpkin puree, eggs, oil and sugar. Once fully mixed add flour, one cup at a time. Lastly add baking powder, baking soda, salt and pumpkin pie spice blend.
In a separate bowl, whisk together cream cheese, egg, sugar and vanilla extract.
Line a 13x9 baking dish with parchment. Pour cake mixture into dish and spread out to the corners.
Use a tablespoon to spoon cream cheese mixture pools evenly over the cake batter. Use a knife to swirl the cream cheese to make a "marble" effect. Sprinkle with walnut pieces. NOTE: Do not push the cream cheese to the base, it will burn.
Bake for 40 minutes or until toothpick comes out clean in the center of cake (not the cream cheese). Cool on a wire rack for at least 30 minutes before using the parchment to remove the cake from the dish. Cut into 18 even squares.