Preheat oven to 350 and line two baking sheets with parchment paper or Silphat baking liners.
Put chopped chocolate in top of double boiler and melt. Set aside to cool.
In small bowl, mix flour, baking powder and salt until blended.
In the bowl of an electric mixer, beat together butter, both sugars and beat until light and fluffy on medium speed.
Beat in melted chocolate.
Add the egg and vanilla and mix until just blended.
Add flour mixture and stir until blended.
Add chocolate chips.
Drop by spoonfulls onto baking sheets and bake for 13-15 minutes.
Cool briefly on pans and then remove to cool on wire racks.