Step 1: Preheat the Oven

Begin by preheating your oven to 160ºC (320ºF) if using a fan-assisted oven, or 170ºC (338ºF) for a conventional oven. Accurate oven temperature is crucial for achieving the perfect browkie texture – a slightly lower temperature ensures that the browkies bake evenly without drying out. While the oven preheats, prepare a baking tray by lining it with parchment paper. Parchment paper prevents the browkies from sticking to the tray and makes for easy cleanup.

Step 2: Melt Chocolate and Butter

In a heatproof bowl, combine the chopped dark chocolate and butter. This step is essential for creating the rich, fudgy base of the browkies. Place the bowl over a pan of simmering water, making sure the bottom of the bowl does not touch the water. This method, known as a double boiler, gently melts the chocolate and butter without burning them. Stir occasionally until the chocolate and butter are fully melted and combined, creating a smooth, glossy mixture. Once melted, remove the bowl from the heat and stir in the vanilla extract. The vanilla extract enhances the chocolate flavor and adds a touch of warmth to the browkies.

Step 3: Whip Eggs and Sugars

In a separate medium bowl, use an electric hand whisk on high speed to beat the caster sugar, demerara sugar, and eggs. This step is crucial for creating a light and airy base for the browkies. Continue whisking until the mixture becomes very light, thick, and fluffy. This process can take several minutes, but it's well worth the effort. The goal is to incorporate as much air as possible into the mixture, which will result in a softer, more tender crumb. You'll know the mixture is ready when it has almost doubled in volume and leaves a ribbon trail when you lift the whisk.

Step 4: Combine Dry Ingredients

In another bowl, sift together the flour, cocoa powder, baking powder, and salt. Sifting the dry ingredients ensures that there are no lumps and that they are evenly distributed throughout the batter. This is especially important for the cocoa powder, which can sometimes clump together. Add the chocolate chips to the dry ingredients and toss them lightly to coat them in flour. This helps prevent the chocolate chips from sinking to the bottom of the browkies during baking.

Step 5: Integrate Chocolate Mixture

Gradually fold the melted chocolate and butter mixture into the whipped eggs and sugars. This step requires a gentle touch to maintain the airiness of the whipped eggs. Add the chocolate mixture in small increments, folding it in with a spatula until just combined. Be careful not to overmix, as this can deflate the mixture and result in tough browkies.

Step 6: Fold in Dry Ingredients

Carefully fold the dry ingredients into the wet mixture using a spatula, ensuring not to deflate the mixture. Mix only until just combined to keep the batter light. It's important to stop mixing as soon as the dry ingredients are incorporated – a few streaks of flour are fine. Overmixing will develop the gluten in the flour, resulting in tough browkies.

Step 7: Bake the Brookies

Scoop tablespoons of batter onto the prepared baking tray, spacing them well apart to allow for spreading. Using a cookie scoop ensures that the browkies are uniform in size, which helps them bake evenly. Bake in the preheated oven for 12-14 minutes, or until the browkies are set and crackly on top. The baking time may vary depending on your oven, so keep a close eye on them. The browkies are done when they are slightly soft in the center but firm around the edges.

Step 8: Cool and Finish

Remove from the oven and sprinkle with sea salt immediately, if desired. The sea salt enhances the chocolate flavor and adds a touch of savory contrast. Let them cool on the baking tray for about 10 minutes before transferring them to a cooling rack to cool completely. Cooling the browkies on the baking tray allows them to firm up without falling apart. Once they are completely cool, they are ready to be enjoyed.