1 cup warm water (110 degrees F/45 degrees C)
1 1/2 tablespoons butter, softened
1/3 cup white sugar
1 egg, beaten
1 teaspoon vanilla extract
1 cup all-purpose flour
1 teaspoon baking soda
1 teaspoon salt
1 cup semisweet chocolate chips
Preheat oven to 350 degrees F (175 degrees C). Grease a 10x15 inch jelly roll pan or baking dish.
In a saucepan, combine water, butter, sugar, egg, vanilla extract, flour, baking soda, and salt. Bring mixture to a boil, stirring frequently. Boil 2 minutes, stirring constantly. Reduce heat to low; continue to boil and stir until mixture is thickened. Beat in chocolate chips. Pour batter into prepared pan.
Bake in preheated oven for 60 minutes.