Toast the pecans for 8 minutes in a 350 degree oven. Cool and place in a food processor. Add flour, sugar, salt and spice. Chop the pecans into small chunks. Add the butter to the mixture and process until the butter is incorporated. Crumble over the pumpkin layer. Bake the bars for 55 minutes or until filling has set and streusel has browned. Cool and refrigerate before slicing. Using the parchment remove the bars from the pan. Trim off the edges if desired. Cut into 16 squares and serve.