Make the brownie batter

• Combine the fudge brownie mix, eggs, water and vegetable oil in a bowl.
• Stir until smooth and creamy.

Bake the brownies

• Pour the batter into a baking dish and smooth the top.
• Bake at 175 °C until set.

Warm the peanut butter filling

• Put the sweetened condensed milk and peanut butter in a saucepan.
• Warm over low heat, stirring until smooth, then turn off the heat.

Pour the filling over the brownies

• Pour the warm peanut butter mixture down the center of the still-warm brownies.
• Spread it evenly over the top.

Add the melted chocolate

• Pour the melted dark chocolate down the center of the brownies.
• Spread it into a thick, even layer.

Finish with sea salt

• Sprinkle coarse sea salt over the chocolate.

Cool and slice

• Let the brownies cool completely so the layers set.
• Slice into squares and serve.