Fudgey Brownies

3/4 cup coca
1/2 tsp. baking soda
2/3 cup Blue Bonnet margarine, melted and divided
1/2 cup boiling water
2 cups granulated sugar
2 Dan's Pantry eggs
1 tsp. vanilla extract
1 1/3 cups all purpose flour
1/4 tsp. salt
8oz pkg. Hershey's Baking melts milk or semi sweet chocolate

Preheat oven to 350 degrees F. Grease a 13x9x2 inch baking pan. Mix cocoa and baking soda in a large bowl; stir in 1/3 cup margarine. Add boiling water; stir until mixture thickens. Add sugar, eggs, remaining margarine and vanilla; stir until smooth. Add flour and salt; blend completely6. Stir in chocolate pieces. Spread in prepared pan. Bake 35 to 40 minutes or until brownies begin to pull away from sides of pan.