On baking sheet, toast walnuts in 350°F oven until fragrant, about 8 minutes. Set aside.
In heatproof bowl over saucepan of hot water (not boiling) water, melt semi-sweet chocolate with butter, stirring occasionally. Let cool slightly.
In large bowl, beat eggs with sugar until pale, about 2 minutes. Stir in vanilla and chocolate mixture.
Whisk together flour, cocoa, baking powder and salt; stir into chocolate mixture. Stir in walnuts, coconut and milk chocolate.
Drop by heaping 1 tbsp, about 2 inches apart, onto parchment paper-lined or greased baking sheets.
Bake in 350°F preheated oven until no longer shiny and tops begin to crack, about 10 minutes. Let cool in pans on racks for 2 minutes, if desired flatten slightly with spatula. Transfer to racks and let cool completely.
Enjoy!
Notes
Recipe source: Canadian Living
Recipe by Salu Salo Recipes at https://salu-salo.com/double-chocolate-walnut-chunk-cookies/