Directions

1. Melt unsweetened chocolate, butter and 1 cup chocolate chips in a 1-quart heavy saucepan over low heat, stirring occasionally. Cool.
2. In a separate bowl, stir together flour, cocoa, baking powder and salt.
3. In a large mixing bowl, beat together sugar, eggs and vanilla with an electric mixer until pale and frothy, about 2 minutes. Mix in the melted chocolate and then the flour mixtures at low speed until combined well. Stir in remaining chocolate chips. Chill, covered, until firm, about 2 hours.
4. Preheat oven to 350°.
5. Roll heaping teaspoons of dough into 1-inch balls with dampened hands and arrange 2 inches apart on ungreased baking sheet. Bake in batches in middle of oven until puffed and set, about 10 minutes (cookies will be soft in the center). Transfer to racks to cool.