Combine pound cake mixes, pie spice and baking soda in a large mixer bowl. Add water, pumpkin and eggs; beat on medium speed for 3 minutes. Spread half of batter into greased 9x13" baking pan; sprinkle with half of the streusel. Carefully spread remaining batter; sprinkle with remaining streusel. Bake in preheated 325~ oven for 50-55 minutes or until tested done.

Streusel Topping: Combine brown sugar, nuts and flour in a medium bowl. Cut in butter with pastry blender or two knives until crumbly.