Preheat and prepare the tray

• Preheat the oven to 180 °C.
• Line and grease the baking tray.

Melt butter and chocolate

• Melt the butter and milk chocolate together in a saucepan over low heat.
• Set aside to cool slightly.

Whisk eggs and sugar

• In a bowl, whisk the granulated sugar and eggs until light and frothy.

Combine the wet ingredients

• Mix the melted chocolate and butter into the egg mixture.
• Add the vanilla and salt.

Fold in the dry ingredients

• Gently fold in the flour and cocoa powder until just combined, without overmixing.
• Fold in the chocolate chunks if using.

Spread the batter

• Spread the brownie batter evenly over the prepared baking tray.

Bake

• Bake for about 38 minutes, until the top is crinkled and a skewer comes out with a few moist crumbs.

Cool and slice

• Let the brownies cool completely in the tray.
• Slice into squares once cool.