Instructions

• Preheat the oven to 180°C (350°F). Grease and line a 10 cm x 20 cm (4×8-inch) loaf pan with aluminum foil, leaving an overhang to lift the cake out later.
• Make the brownie layer: place 140 g dark chocolate and 50 g unsalted butter in a heatproof bowl over low heat (or directly in a small saucepan on the lowest setting). Stir gently until fully melted and smooth. Remove from heat.
• Stir 50 g brown sugar into the melted chocolate mixture until combined. Let the mixture cool for 2–3 minutes so it is warm but not hot.
• Add 1 egg to the chocolate mixture and beat or stir until fully incorporated and smooth.
• Fold in 35 g all-purpose flour until just combined and the batter is smooth. Scrape the batter into the prepared loaf pan and smooth the surface.
• Bake the brownie layer at 180°C (350°F) for 15 minutes. Remove the pan from the oven and immediately reduce the oven temperature to 160°C (320°F). Let the brownie layer rest in the pan for 5–10 minutes so it is set but still warm.
• Meanwhile make the butter cake batter: beat 120 g unsalted butter with 100 g sugar until the mixture is creamy and pale. Add the 2 eggs one at a time, beating well after each addition.
• Sift together 120 g all-purpose flour and 2 g baking powder. Fold the sifted dry ingredients into the butter-egg mixture in two additions, alternating with the 50 ml fresh milk (for example: half the flour, all the milk, then the remaining flour). Mix until the batter is smooth and homogeneous.
• Spoon and spread the butter cake batter evenly over the warm brownie layer in the pan, smoothing the top.
• Bake at 160°C (320°F) for 25–30 minutes, or until a skewer or cake tester inserted into the center comes out clean or with a few moist crumbs.
• Remove the pan from the oven and cool on a wire rack for 10–15 minutes. Use the foil overhang to lift the cake from the pan and cool completely on the rack before slicing.