Step 1

Heat oven to 350°F.

Step 2

Chop 8 oz. chocolate; set aside. Microwave remaining chocolate in large microwaveable bowl on HIGH 2 min., stirring after 1 min.; stir until chocolate is completely melted. Add butter; stir until melted. Stir in sugar, eggs and vanilla. Add flour and baking powder; mix well. Stir in chopped chocolate and nuts. (Note: If omitting nuts, increase flour to 3/4 cup to prevent excessive spreading of cookie dough as cookies bake.)

Step 3

Drop rounded tablespoonfuls of dough, 2 inches apart, onto baking sheets.

Step 4

Bake 12 to 13 min. or until cookies are puffed and shiny. Cool on baking sheets 1 min. Remove to wire racks; cool completely.