In a small saucepan over very low heat on the stove, melt the butter. Coarsely chop half (about 160 grams) of the chocolate chunks. Add to the saucepan and heat, stirring often, until melted and smooth. Remove from the heat and let cool to lukewarm.
Prepare the grill for indirect cooking over medium heat (about 180ºC).
In a large bowl using an electric mixer set on high speed, beat the eggs, brown sugar, and vanilla until pale yellow and fluffy, 2 to 3 minutes. Beat in the cooled butter-chocolate mixture.
In a medium bowl sift the flour, cocoa powder, baking powder, and salt. Gradually stir into the large bowl of batter. Add the walnuts, coconut flakes, raisins and/or cherries, and the remaining chocolate chunks; stir to blend. The batter will be stiff.
Use a tablespoon and wet fingertips to drop 2.5-centimeter mounds of the batter onto a cookie sheet lined with parchment paper, keeping the mounds about 5 centimeters apart (the cookies do not spread when baked). Grill, in batches, over indirect medium heat, with the lid closed,keeping the grill's temperature as close to 180ºC as possible, until the cookies look and feel set, about 20 minutes. Remove from the grill and let the cookies cool on the cookie sheet until they are easy to remove with a spatula, 2 to 3 minutes. Transfer the cookies to a cooling rack and allow them to cool completely. Repeat with the remaining dough and a cool, parchment-lined baking sheet. Makes about 36 cookies.
Use a tablespoon and wet fingertips to drop 2.5-centimeter mounds of the batter onto a cookie sheet lined with parchment paper, keeping the mounds about 5 centimeters apart (the cookies do not spread when baked). Grill, in batches, over medium heat, with the lid closed,keeping the grill's temperature as close to 180ºC as possible, until the cookies look and feel set, about 20 minutes. Remove from the grill and let the cookies cool on the cookie sheet until they are easy to remove with a spatula, 2 to 3 minutes. Transfer the cookies to a cooling rack and allow them to cool completely. Repeat with the remaining dough and a cool, parchment-lined baking sheet. Makes about 36 cookies.
