Brownies

Preheat your oven to 175°C (350°F) with a rack positioned in the middle. Line a 20cm (8-inch) square baking pan with parchment paper, leaving 5cm (2-inch) overhang on two opposite sides for easy lifting later; lightly grease any exposed pan edges with a thin coating of butter.

Chop the 170g dark chocolate into small, even 1cm pieces, then combine with 113g cubed unsalted butter in a completely dry heatproof bowl. Set the bowl over a small saucepan of gently simmering water (double boiler setup: ensure no water touches the bottom of the bowl, as this will seize the chocolate) and stir constantly over medium-low heat for 3-4 minutes until fully smooth and melted; remove from heat immediately.

Let the melted chocolate mixture cool for 5 minutes until it is warm, not hot, to the touch (around 45°C / 113°F) to avoid cooking the eggs when added. Stir in 200g granulated sugar until fully combined, then add the 2 room-temperature eggs one at a time, stirring vigorously for 30 seconds after each addition, followed by 5ml pure vanilla extract, until the batter is thick, glossy, and pulls away slightly from the sides of the bowl.

Sift 65g all-purpose flour, 30g unsweetened cocoa powder, and 1g fine sea salt directly into the chocolate batter. Use a silicone spatula to fold the dry ingredients in gently with slow, scraping turns from the bottom of the bowl, stopping after 10-12 strokes just as no dry flour streaks remain; do not overmix, as overdeveloping gluten will create dry, cakey brownies instead of fudgy ones. Fold in 85g semi-sweet chocolate chips with 2-3 extra strokes, if using.

Pour the finished batter into the prepared 8-inch square pan, spreading it into a smooth, even layer with your spatula, and gently tap the pan on the counter 2-3 times to release any trapped air bubbles. Bake on the middle oven rack for 22-25 minutes at 175°C (350°F). Test for doneness by inserting a wooden toothpick 2.5cm (1 inch) from the pan edge: it should come out with moist, fudgy crumbs attached, not raw wet batter and not completely clean, dry crumbs.

Remove the pan from the oven and set it on a wire cooling rack to rest for 30 minutes at room temperature, until the brownies are fully set and firm to the touch. Use the parchment paper overhang to lift the entire brownie slab straight out of the pan, set it on a wooden cutting board, and slice into 9 equal 6cm (2.5-inch) squares with a sharp knife, wiping the blade clean with a paper towel between cuts for smooth, neat edges.