Get Ready: Preheat your oven to 350°F (175°C). Lightly grease an 8x8 inch (20cm) square baking pan and line it with parchment paper, leaving an overhang to easily lift the brownies later.
Melt & Mix: In a microwave-safe bowl or using a double boiler, gently melt the bittersweet chocolate and butter together until smooth and glossy. Stir them well to combine.
Sweeten It Up: Whisk in the brown sugar until combined, then add the eggs one at a time, mixing thoroughly after each addition until the batter looks thick and shiny.
Fold in Dry: Sift the flour and cocoa powder directly into the wet ingredients. Carefully fold them in until just barely combined – be sure not to overmix! If you're adding nuts or other mix-ins, stir them in now.
Bake to Perfection: Pour the batter evenly into your prepared pan. Bake for about 40 minutes, or until a toothpick inserted into the center comes out with just a few moist crumbs, ensuring a wonderfully fudgy brownie.
Cool & Cut: Let the brownies cool completely in the pan before removing them. Once cooled, carefully lift them out and cut them into festive triangle shapes that look like little Christmas trees.
Decorate with Joy: Melt white chocolate and tint a portion of it with green food coloring. Drizzle the green chocolate in cheerful zigzag patterns over each brownie tree, creating charming 'garlands.'
Sparkle & Serve: While the chocolate is still soft, generously add Christmas sprinkles as 'ornaments.' Let the chocolate set completely. For a fun, handheld treat, insert popsicle sticks into the base of each tree. Enjoy your adorable and delicious holiday dessert!