90g all-purpose flour; ¼ tsp baking soda; ½ tsp salt; 100g granulated sugar; 3 tbsp unsalted butter; 2 tbsp whole milk; 450g milk chocolate chips; 2 large eggs; ½ tsp pure vanilla extract; your favourite vanilla ice cream, for serving; chocolate sauce, fo
1. Preheat the oven to 325°F/165°C, with a rack in the middle position. Butter an 8-by-8-in [20-by-20-cm] square baking pan and set aside.
2. In a small bowl, whisk the flour, baking soda, and salt. Set aside.
3. In a medium saucepan over medium heat, combine the sugar, butter, and milk. Bring to a boil. Remove the pan from the heat and add 270g of the chocolate chips. Stir until the chocolate is melted and smooth.
4. Add the eggs and vanilla to the chocolate. Stir until blended and smooth.
5. Gradually add the flour mixture to the chocolate, stirring until just combined. Spread the batter evenly into the prepared pan. Sprinkle the top of the batter with the remaining 180g of chocolate chips.
6. Place the pan in the oven and bake for 25 to 30 minutes, rotating the pan about halfway through the baking time to ensure even cooking, until the brownies are set and the edges looked baked.
7. Remove the brownies from the oven and place on a wire rack to cool in the pan. Cut the brownies into six large squares. Serve topped with vanilla ice cream and chocolate sauce, if desired.