Blanch asparagus in boiling water 1 to 2 minutes or until crisp-tender. Rinse in cold water; drain. (If asparagus is thin, use 2 pieces per appetizer and skip the blanching process.)
Unfold pastry sheet onto a lightly floured surface, and press out fold lines. Roll into a 12- x 10-inch rectangle. Cut into 12 (1-inch) strips.
Wrap 1 or 2 asparagus spears in 1 slice of prosciutto, and wrap with 1 strip of pastry dough. Place on a parchment-lined or greased, foil-lined baking sheet. Repeat with remaining pastry, asparagus, and prosciutto. Sprinkle wraps with Parmesan cheese.
Bake at 400° for 12 minutes or until golden brown.