Begin by melting 1 cup of the chocolate chips in a microwave-safe bowl. Stir the melted chocolate until smooth. In a separate bowl, combine the softened butter and granulated sugar, beating until the mixture becomes crumbly, approximately 2 minutes. Incorporate the egg whites and vanilla extract, mixing thoroughly before adding the melted chocolate.

In another bowl, whisk together the all-purpose flour, baking powder, and salt. Gradually incorporate this dry mixture into the butter mixture, alternating with the water. Finally, fold in the remaining 1 cup of chocolate chips. Cover the dough and refrigerate for about 2 hours, or until it is manageable.

Preheat your oven to 350°F (175°C). Shape the chilled dough into 1-inch balls and roll them in the confectioners' sugar until well coated. Arrange the cookies on baking sheets that have been lightly sprayed with cooking spray, ensuring they are placed 2 inches apart. Bake the cookies for 10 to 12 minutes or until they are set. Once baked, transfer them to wire racks to cool completely.