Chocolate Chess Pie

1 1/2 cups granulated sugar
3 tablespoons cocoa
2 eggs, beaten
1 (5.3 ounce) can evaporated milk
1/4 cup margarine, melted
1 teaspoon vanilla extract
1 1/2 to 2 cups chopped pecans
1 (9-inch) pie shell

Blend sugar and cocoa. Add eggs and milk. Mix well. Stir in margarine and vanilla extract. Add pecans. Stir well. Pour into unbaked pie shell. Bake at 350 degrees F for 50 minutes.