Saute pecans in butter, stirring constantly, about 5 minutes or until roasted. Set aside to cool.
Combine 1 cup brown sugar, eggs, evaporated milk, and milk in a large saucepan. Cook over medium heat, stirring constantly, 20 minutes or until mixture reaches 160° F (do not boil). Remove from heat; let cool. Stir in sweetened condensed milk and vanilla. Cover and chill at least 1 hour. Fold in whipped cream.
Place remaining 1 cup brown sugar in a small saucepan; cook over medium heat, stirring mixture constantly, until sugar dissolves and forms a smooth liquid. Stir in the sauteed pecans. Stir pecan mixture into custard; break apart pecan lumps.
Pour into 5 quart ice cream freezer and freeze according to manufacturer's instructions. Let harden for 1 hour before serving.