Cream butter and sugar in large mixing bowl for 5 minutes. Add eggs, one at a time, beating well after each addition. Sift together flour, baking powder, and salt. Add the flour mixture alternately with chocolate syrup. Add vanilla. Spread batter in a greased and floured 9"x13" baking pan. Bake at 350 degrees for 35 minutes or until center is firm to the touch. Remove from oven; cool slightly. Spread chocolate frosting over top.

Chocolate Frosting

Place butter, sugar and milk in a small saucepan. Stir over low heat until sugar is dissolved, about 2 1/2 to 3 minutes. Remove from heat and add chocolate chips. Stir until smooth. Spread over top of warm cake. Serve warm or cold.