Preheat oven 150ºC . In double boiler, over hot but not boiling water, (or microwave), melt semisweet chocolate. Set aside to cool to room temp. In sm bowl, shisk together flour, baking soda, and salt. In med bowl, whisk together sugars. Add butter and beat until well combined. Add peanut butter and beat until smooth. Add eggs and vanilla; beat until just combined. Add flour mixture and milk chocolate chips; beat until no streaks of flour are visible. Pour in melted chocolate; mix partially with a wooden spoon until marbled. Drop dough in 3T mounds, 5 cm apart on ungreased baking sheet. Top with one whole peanut. Bake 23 mins or until just set but still soft. Cool on cookie sheet 30 sec, then transfer to wire rack.