Preheat oven to 350 degrees F (175 degrees C). Grease and flour an 8x8 inch pan.

In a small saucepan over medium heat, melt margarine and cocoa together, stirring occasionally until smooth. Remove from heat and set aside to cool.

In a large bowl, beat eggs until frothy. Stir in the sucrolose sweetener. Combine the flour and salt; stir into the egg mixture then mix in the cocoa and margarine. Stir in the 1/4 cup of milk and, if desired, the walnuts.

Pour batter into prepared pan. Bake for 25 to 30 minutes in the preheated oven, until a toothpick inserted into the center, comes out clean.

Prepare frosting by mixing sugar-free chocolate pudding mix and 1 cup skim milk using an electric mixer. Mix for about two minutes or until thick.