Prepare the grill for indirect cooking over low heat (keep the grill as close to 150ºC as possible). Generously grease a 23-by-23-centimeter metal baking pan with 1 tablespoon of the butter, paying special attention to the bottom and sides.
In a medium bowl sift the flour, cocoa powder, baking powder, and salt.
In a medium saucepan over medium heat on the stove, melt the remaining 225 grams butter. Remove from the heat. Whisk the sugar into the melted butter until evenly blended. Whisk in the eggs, one at a time, blending well after each addition. Add the vanilla. Whisk in the flour mixture in two additions until smooth. Fold in the chocolate chips and all but about 1 tablespoon of the crushed candy canes. Pour the batter into the prepared pan. Smooth the top. Sprinkle the reserved crushed candy canes over the batter.
Cook the brownies over indirect low heat, with the lid closed, until a toothpick inserted into the center comes out clean, 40 to 50 minutes. Cool completely in the pan on a wire rack. Dust with confectioners' sugar and cut into squares. Top with whipped cream, if desired.
Cook the brownies over low heat, with the lid closed, until a toothpick inserted into the center comes out clean, 40 to 50 minutes. Cool completely in the pan on a wire rack. Dust with confectioners' sugar and cut into squares. Top with whipped cream, if desired.
