Preheat the oven to 375 degrees F. Melt and combine the chocolate and butter in a bowl set over simmering water. Remove from the heat and whisk in the corn syrup and sugar. Whisk in the eggs, salt and vanilla. Place the cashews in the pie shell. Pour in the chocolate mixture. Bake for 35-40 minutes, or until the filling is just set. Cool to room temperature. Serve slices with a dollop of whipped cream and garnish with a few whole cashews, if desired.