In microwave, melt 1 cup of the chocolate chips. Stir until smooth and then set to the side to cool slightly. In separate bowl, cream butter and sugar until slightly crumbly. Add the egg whites and vailla, mixing well.
Add melted chocolate. In separate bowl, combine flour and baking powser. Gradually add the flour mixture to the butter mixture, alternating with water. Stir in remaining chocolate chips. Cover dish and refrigerate for about 2 hours or until the dough is easy to handle.
Preheat oven to 350. Shape chilled dough into 1 inch balls. Roll in powdered sugar. Place about 2" apart on baking sheet. Bake 10-12 minutes or until set. Cool on rack.