Heat oven to 375°F. In 10-inch skillet, heat 1/2 inch water to boiling. Add asparagus; reduce heat to medium-low. Cover; simmer 2 to 3 minutes or until crisp-tender. Drain. Plunge asparagus into bowl of ice water to cool; drain on paper towels.
If using crescent rolls: Unroll dough on ungreased cookie sheet; press into 11x8-inch rectangle, firmly pressing perforations to seal. With fork, prick crust generously. If using dough sheet: Unroll dough on ungreased cookie sheet; press into 11x8-inch rectangle. With fork, prick crust generously.
Bake 6 to 9 minutes or until light golden brown.
Sprinkle with 1/2 cup of the cheese; top with prosciutto strips. Sprinkle with remaining 1 cup cheese. Arrange cooked asparagus spears in rows over cheese, alternating tips. Brush with oil; sprinkle with pepper flakes.
Bake 5 to 7 minutes longer or until edges of crust are deep golden brown and cheese is melted. Cool 5 minutes. With serrated knife, cut into 6 rows by 4 rows. Serve warm.