Melt the butter and chocolate in a double boiler or slowly in a pot over low heat. Remove from heat once the chocolate melts. Stir it often. Chocolate burns and sticks easily. Mix together the eggs, sugar, salt, corn syrup, butter extract, and vanilla. Whisk in the melted chocolate to the egg mixture. Stir in the pecans. Rub 1 - 2 tablespoons of softened butter on the bottom of the pie crust. Sprinkle 1 to 2 tablespoons of sugar on top of the butter. Pour in the chocolate mixture. Bake at 350 degrees for 30 to 35 minutes or just until the filling is set. It will be soft to touch. Serve warm with vanilla ice cream or whipped cream.