Place oven rack in the lower one-third of oven; preheat oven to 400°. Spray a deep-dish 8-inch pie plate with nonstick spray; set aside.

Cook sausage in a medium nonstick skillet over medium heat for 3 to 5 minutes or until browned (165°), stirring occasionally to break into crumbles. Drain, if necessary, transfer to a large bowl. Add green pepper and onion to same skillet and cook for 2 to 3 minutes or until softened, stirring occasionally. Add green pepper mixture to sausage.

Unroll each pie pastry onto a separate sheet of parchment paper. Roll each into a 13-inch circle with a rolling pin. Fold one pie pastry in fourths and place in prepared pie plate. Unfold pie pastry and ease it into the pie plate. Trim pastry even with plate rim; set aside. Cut a jack-o’-lantern face in the middle of the remaining pie crust pastry; set aside.

Add sauce, pepperoni, 1¾ cups mozzarella, three cheese blend, black olives, and Italian seasoning to sausage mixture in bowl; stir to combine. Transfer mixture to the pastry-lined pie plate. Sprinkle with remaining ¼ cup mozzarella cheese. Gently roll the cutout pastry around a rolling pin; carefully unroll to place it on top of the filling. Trim the top pastry ½-inch beyond the edge of the pie pan. Fold top pastry edge under the bottom pastry edge. Crimp edges of pastries together. Brush top pastry with egg.

Bake for 40 to 45 minutes or golden brown and filling is bubbling. If necessary, cover edge of pie with foil to prevent overbrowning. Cool on a wire rack for 10 minutes before serving. Garnish with basil, if desired.