Meanwhile, reduce the oven to 250 degrees.
06In small mixing bowl, beat egg whites to stiff peaks, then slowly beat in superfine sugar until completely dissolved.07Fold in cooled coconut. Press this mixture into greased 9-inch pie plate and bake at 250 degrees for 7 minutes and set. Remove from oven and let cool.08To make filling:09Blend together sweetened condensed milk, lime juice, lime rind and rum in large mixing bowl.10Beat in the egg yolks.11Gently mix in sour cream to combine well.12Pour into cooled crust. Swirl meringue over top of filling.13Bake in 350 degrees oven 20 minutes or until meringue is nicely browned.14Cool, then chill at least 30 minutes before serving.15To make Meringue:16Beat egg whites in large mixing bowl until soft peaks are formed.17Gradually beat in sugar until whites are stiff, but not dry, being sure the sugar is dissolved.