Heat oven to 400°F. Coat baking sheet with nonstick cooking spray.
In large bowl, combine thawed spinach soufflé, ham and cheese.
Unroll tube of refrigerated pizza crust into 10-inch square; if necessary roll out with rolling pin. Cut into four 5-inch squares. Spoon 1/2 cup spinach mixture onto each square; spread into a triangle to cover half. Fold dough over filling to form triangle. Roll edge over once to seal. Invert onto prepared baking sheet. With fork, press edges to seal. Repeat with remaining filling and dough.
Bake in 400°F oven until calzones are browned and filling is hot, about 20 minutes. Let stand 5 minutes before serving.