Place chopped pecans on a parchment-lined baking sheet and bake at 350°F, just until they become aromatic, about 5 minutes. Allow to cool before adding to piecrust.

Unroll piecrust onto a surface dusted with powdered sugar; sprinkle with toasted chopped pecans.

Place a sheet of wax paper over piecrust and pecans, and gently roll, pressing pecans into crust.

Fit piecrust, pecan side up, in a lightly greased pie plate. Fold the edges under, and *crimp.

*if desired instead of crimping, use a leaf design pastry cutter to cut out a decorative leaf edge for your pie from the second piecrust in package. Cut out leaves from entire piecrust, rerolling the scraps. Apply leaves to edge of pie, lightly pressing the bottoms of the leaves into piecrust to attach, overlapping leaves slightly until edge of pie is covered. Bake any leftover leaves on a parchment lined baking sheet for 8 - 10 minutes or until golden, while pie is baking. Allow leaves to cool on wire rack and use a garnish for pie.

Stir together pecan halves and pieces, brown sugar, flour, melted butter, and pumpkin pie spice in a medium bowl until well combined.

Whisk together pumpkin and next 6 ingredients in a large bowl until smooth and well incorporated; pour into prepared piecrust.

Bake at 350° for 45 minutes, shielding edges with aluminum foil after 20 minutes, if needed, to prevent excessive browning.

Remove pie from oven and carefully top pie with Pecan Streusel Topping. Reduce oven temperature to 325°, and return pie to oven and bake 25 minutes, covering pie with aluminum foil after 5 to 10 minutes to prevent excessive browning. Cool completely on a wire rack (about 2 hours).