Heat oven to 375°F. Remove pie crust from pouch; unroll on ungreased cookie sheet.
In medium bowl, mix flour, sugar, brown sugar, ginger, cinnamon and nutmeg. With pastry blender or fork, cut in butter until mixture resembles coarse crumbs. Stir in 1/4 cup macadamia nuts.
Sprinkle half of the crumb mixture over crust to within 1 inch of edge. Top with crushed pineapple and halved pineapple slices. Sprinkle with remaining crumb mixture. Fold in pie crust edge 1 inch to form border; flute.
Bake 25 to 35 minutes or until crust is golden brown. Cool 30 minutes.
Meanwhile, in 1-quart saucepan, heat caramel topping over low heat, stirring occasionally, until warm. Stir in 1/2 cup macadamia nuts and the rum. Cut warm galette into 8 wedges; place on dessert plates. Spoon 2 tablespoons warm sauce over each serving.