Heat oven to 350°. Coarsely chop 4 squares of chocolate and set aside. Line 9-inch pie plate as directed on package with pie crust. Microwave remaining 4 squares of chocolate and butter in large microwavable bowl on high 1 to 2 minutes or until butter is melted. Stir until chocolate is completely melted. Brush bottom of pie crust with small amount of beaten egg. Stir sugar, corn syrup, eggs and vanilla into chocolate mixture until well blended. Stir in pecans and chopped chocolate. Pour into pie crust. Bake 55 minutes or until knife inserted 2 inches from edge comes out clean. Cool on wire rack.