Preheat oven to 360 degrees F (180 degrees C).
Grease and line an 8-inch square pan with parchment paper.
Melt Valrhona® 66% Dark Chocolate (280 gram), Butter (110 gram) and Valrhona® Cocoa Powder (1 tablespoon) over low heat till chocolate melts, but do not boil the chocolate, and stir in Brown Sugar (80 gram) and stir well again and remove from heat and allow to cool slightly.
Gently fold in Cake Flour (70 gram) to just combined and do not over beat. Add in beaten Egg (2) and Vanilla Extract (1 teaspoon), stir well. Spread chocolate batter into prepared pan.
Sprinkle with Canned Pineapple Slices in Juice (5 slice) over the top, followed by Walnut (80 gram) and Chocolate Chips (35 gram).
Bake in oven at 360 degrees F (180 degrees C) for about 30 minutes.
After cooling, chill the brownies for at least an hour for easy cutting. Enjoy!