Preheat the oven and prepare the tray

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

Melt the butter and chocolate

• Melt the butter and milk chocolate together.
• Set aside to cool slightly.

Whisk the eggs and sugar

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

Combine the wet ingredients

• Mix in the melted chocolate and butter.
• Add the vanilla extract and salt.

Fold in the dry ingredients

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

Bake the brownies

• Spread the batter evenly in the prepared baking tray.
• Bake for 35–38 minutes.

Cool and slice

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