Heat oven to 450°F. Place pie crust in 9-inch tart pan with removable bottom as directed on box for One-Crust Filled Pie. Press in bottom and up sides of pan. Trim edges if necessary. Do not prick crust.
Bake 10 to 12 minutes or until golden brown. If crust puffs in center, flatten gently with back of wooden spoon. Cool. Reduce oven temperature to 375°F.
In medium bowl, beat egg and brown sugar with electric mixer on medium speed until well blended. Beat in butter, corn syrup and rum. Stir in macadamia nuts and chocolate chips. Pour filling into partially baked crust.
Bake 25 minutes or until deep golden brown and center is almost set. Cool completely on cooling rack. Remove side of pan; cut tart into 8 wedges. Drizzle with melted chocolate.