Melt the butter and mix with flour, sugar and salt.
Press the pulp into a pie mold with a removable bottom or spring mold, about 24 inches in diameter. Chop the bottom with a fork. Bake for about 15 minutes.
Filling: Mix cream, sugar, syrup and brown sugar in a saucepan and simmer for about 10-15 minutes, stirring occasionally but not all the time. Fit towards the end so that it does not burn to the bottom.
Add the butter and stir until everything is mixed.
Pour the charcoal over the pie shell and spread the nuts over. Let cool and set.
Serving: Serve the pie with lightly whipped cream.