Method

• Prepare the Pan.
• Position an oven rack in the center and preheat the oven to 325°F (163°C). Line the 9 x 9-inch (23 x 23 cm) metal baking pan with parchment paper, leaving an overhang on opposite sides. Press the parchment into the corners so the brownie batter will spread evenly and the baked slab can be lifted out without breaking.
• Combine the Butter and Sugar.
• Melt the unsalted butter in a saucepan over low heat until fully liquid but not browned, about 2 to 3 minutes. Transfer it to the large heatproof mixing bowl. Add the vegetable oil and granulated sugar, then whisk for 1 to 2 minutes until the mixture looks thick, glossy, and evenly moistened. Some sugar granules will remain visible.
• Incorporate the Eggs and Vanilla.
• Allow the butter mixture to cool until warm rather than hot, then add the eggs one at a time, whisking after each addition. Add the vanilla extract and whisk for another 30 to 60 seconds, until the batter looks smoother and slightly thickened. This mixing distributes the egg proteins and encourages a stable emulsion without cooking the eggs.
• Fold in the Dry Ingredients.
• Add the sifted cocoa powder, all-purpose flour, and fine table salt to the medium mixing bowl and stir briefly to distribute them. Add the dry mixture to the wet ingredients and fold gently with the silicone spatula for about 30 to 60 seconds, stopping when no dry flour remains. The batter should be thick, dark, and glossy; avoiding excessive mixing limits gluten development.
• Spread and Bake the Brownies.
• Transfer the batter to the prepared pan and smooth it into an even layer, pushing it gently into the corners. Bake at 325°F (163°C) for approximately 35 to 40 minutes. The edges should be set, the surface should appear slightly crackled, and a toothpick inserted into the center should come out with moist crumbs but no liquid batter. Begin checking near the shorter end of the baking range to avoid drying out the center.
• Cool and Chill the Brownies.
• Place the pan on a wire rack and allow the brownies to cool for approximately 90 minutes, until they reach room temperature and the center has firmed up. Refrigerate the pan for another 30 minutes. This cooling and chilling period allows the chocolate-rich structure to set so the sticks hold their shape when sliced.
• Prepare the Chocolate Dip.
• Place the semisweet chocolate chips in the small heatproof bowl. Heat the heavy whipping cream in the clean saucepan over medium-low heat for approximately 3 to 5 minutes, until it steams and small bubbles appear around the edges, without reaching a rolling boil. Pour the hot cream over the chocolate chips and let stand for 5 minutes. Stir slowly from the center outward until the chocolate melts into a smooth, glossy ganache. Allow it to cool slightly until it thickens enough to coat a brownie stick.
• Slice Into Brownie Sticks.
• Lift the chilled brownie slab from the pan using the parchment overhang and transfer it to a cutting board. Remove the parchment, then use a long, sharp knife to cut the slab into 9 strips, each approximately 1 inch (2.5 cm) wide. Cut each strip crosswise in half to make 18 sticks, approximately 1 x 4 1/2 inches (2.5 x 11.5 cm). Wipe the knife between cuts to prevent sticky crumbs from dragging across the surfaces.
• Serve With Warm Chocolate Dip.
• Transfer the brownie sticks to a serving plate and pour the warm ganache into a serving bowl. Let the ganache stand briefly if it seems too thin; it should flow slowly from a spoon and coat the brownies without immediately running off. Serve the sticks alongside the dip while the ganache remains soft and glossy.