Preheat oven to 400°.
Arrange squash pieces in a single layer on a jelly-roll pan. Drizzle with oil, stirring to coat. Bake at 400° for 1 hour and 20 minutes or until squash is tender and beginning to brown, stirring every 20 minutes.
Transfer squash to a bowl. Add juice, sugar, brandy, 1 tablespoon butter, cinnamon, and salt. Mash mixture with a potato masher until combined and fairly smooth. Stir in currants. Scrape squash mixture into an 8-inch square baking dish coated with cooking spray.
Combine flours in a small bowl; cut in 2 tablespoons chilled butter with a pastry blender or 2 knives until mixture resembles coarse meal. Stir in pecans. Sprinkle pecan mixture evenly over squash mixture. Bake at 400° for 30 minutes or until thoroughly heated and topping begins to brown. Serve warm.