Preheat oven to 350F degrees. Spray a 9x13 pan with oil.
In a bowl, combine pumpkin, milk, eggs, stevia, salt, and pie spice. Pour into pan.
In another bowl, whisk egg and vanilla.
Add flour and stevia to egg and vanilla. Using a pastry blender or food processor, mix until it becomes a fine crumble. Add the chopped pecans. Cut in the cold butter with the pasty blender or whiz the processor until just incorporated - pea-sized crumbles.
Evenly sprinkle the dry mix over the batter.
Bake uncovered for 25 minutes then cover with foil and bake an additional 15-20 minutes.
Cool and cut into squares. Serve with fresh whipped cream or Redi-Whip