Instructions

• Preheat the oven to 180°C / 350°F on the conventional (no fan) setting and place a rack in the middle position.
• Spray an 8‑inch (20 cm) square cake pan lightly with baking oil and set it aside.
• Peel and place the 3 medium ripe bananas in a large bowl. Mash them with a fork until creamy and mostly smooth (or use a blender/stick blender).
• If the 225 g hazelnut chocolate spread is firm, warm it until pourable: heat briefly in the microwave in 10–15 second bursts, stirring between bursts, or loosen by placing the jar in warm (not boiling) water. Do not overheat.
• Pour the warmed 225 g hazelnut chocolate spread into the bowl with the mashed bananas.
• Add the 90 g unsweetened Dutch cocoa powder to the bowl.
• Stir everything with a spatula until fully combined and uniform in color and texture.
• Pour the batter into the prepared 8‑inch pan and level the top with the spatula. Sprinkle a pinch of Fleur de Sel on the surface, if using.
• Bake on the middle rack for 20 minutes, then check doneness: insert a toothpick into the center—you're looking for it to come out with very moist crumbs clinging to it (not wet batter) for a fudgy texture.
• If the center is still too wet, continue baking for an additional 10–15 minutes, checking periodically.
• Remove the pan from the oven and allow the brownies to cool completely in the pan.
• For best texture, refrigerate the cooled brownies in the pan for at least 30 minutes. Cut into 9 squares and serve.