Preheat oven to 375 °F. Grease and flour two 9 inches heart shape cooking pans; set aside. In a small bowl, combine flour, baking soda and salt; set aside. In a large mixing bowl, cream together butter and sugars until light and fluffy; beat in eggs and vanilla extract. Gradually blend in flour mixture. Stir in chocolate chips. Press half of the dough into the bottom of one prepared pan in an even layer; repeat this with the second prepared pan. Bake 25 to 30 minutes or until golden brown. Cool for 20 minutes in the pans on wire rack. Invert pans to release cookies, and return to wire rack topside up. Allow to cool completely before decorating. Transfer frosting to a medium pastry bag fitted with a plain #7 tip. Decorate cookies as you desired.
Frosting: Place chocolate chips in a medium bowl. Set aside. Place evaporate milk in a saucepan over medium heat. Bring to a simmer. Pour half over chocolate chips, let sit for 1 minute. Whisk gently to smooth. Add remaining half; whisk gently until just combine. Leave out at room temperature, stirring occasionally until consistency of toothpaste, about 1 hour.
Mom's Note: You can cook this at lower temperature if desired, at 350 °F for 30 to 40 minutes or until golden brown.