1 1/2 cups white sugar
1 1/2 cups vegetable oil
1 teaspoon vanilla extract
2 eggs
3 cups all-purpose flour
1 cup butter, melted
1 teaspoon baking soda
1 tablespoon milk
Preheat oven to 350 degrees F (175 degrees C). Grease and flour 2 (9 inch) pans.
Turn off heat in oven. Stir together sugar, vegetable oil, vanilla extract and eggs.
Sift together the flour, 1/2 cup and melted butter into one cup of the sugar mixture. Stir in the flour mixture. Gradually stir in the cocoa mixture. Stirring constantly until well blended, press half of the mixture in first place, then continue with remaining mixture and chocolate chunk on top. Spread evenly.
Bake in preheated oven for 60 minutes, or until toothpick inserted in center comes out clean. Cool in pan on wire rack for 30 minutes, then turn over and cool completely. Transfer to refrigerator.
To make the icing glaze: Beat 1 cup of sugar and 1 1/2 cups butter in small bowl. Mix together 2 tablespoons cocoa, 1 tablespoon lemon juice and 1 teaspoon melted butter. Chill icing in refrigerator at least 1 hour, stirring occasionally