In a small bowl, combine the first six ingredients. Prepare pie crust mix according to package directions; divide dough in half.
Roll each portion into a 14x8-in. rectangle on lightly floured pieces of waxed paper. Spread half of pumpkin mixture over one rectangle to within 1/4 in. of edges. Roll up tightly jelly-roll style, starting with a long side. Wrap in waxed paper. Repeat with remaining dough. Freeze 30 minutes or until firm.
Preheat oven to 400°. Using a sharp serrated knife, trim ends and cut dough crosswise into 1/4-in. slices. Place 1 in. apart on parchment paper-lined baking sheets. Bake 18-22 minutes or until light golden. Remove from pans to wire racks to cool completely.
In a small bowl, combine frosting and enough milk to reach a drizzling consistency. Drizzle over pinwheels; let stand until set. Store between pieces of waxed paper in airtight containers. Freeze option: Place wrapped logs in a resealable plastic freezer bag; return to freezer. To use, unwrap frozen logs and cut into slices. If necessary, let dough stand 15 minutes at room temperature before cutting. Bake as directed, increasing time by 2-4 minutes.