1 c. unsalted butter
1 1/2 c. sugar
3 eggs
1 1/2 tsp. vanilla
1 c. pareve milk
3 c. flour
2 tsp. baking powder
1/2 tsp. salt
3/4 c. chocolate syrup

Cream butter and sugar. Add eggs one at a time. Add vanilla and baking powder. Alternately add the flour and pareve milk. Pour 3/4 of batter into 9x13 inch pan. Add chocolate syrup to the remaining batter. Pour over white batter and swirl gently with a knife. Bake at 350 degrees for 45 minutes - 1 hour.