Preheat oven to 325F. Microwave chocolates and butter in large microwaveable bowl on HIGH 2 min. or until butter is melted. Stir until chocolate is completely melted.
Add sugar; mix well. Blend in eggs and vanilla.
Add flour, baking powder and salt; mix until well blended. Stir in pecans.
Drop rounded tablespoonfuls of dough, 2 inches apart, onto baking sheets.
Bake 12 min. or until cookies feel set to the touch. Cool 1 min.; remove from baking sheet. to wire racks. Cool completely. Store in tightly covered container at room temperature for up to 1 week.