• Preheat the oven to 350°F (175°C) or 160°C fan, about 8–10 minutes before placing the shaped rolls in the oven.
• Grease or line an 8 inch (20 cm) square baking pan.

Make the Banana Filling

• In a small saucepan, combine mashed banana, brown sugar, and cinnamon.
• Cook over medium heat for 3–5 minutes, stirring frequently, until thick and glossy.
• When you pull a spatula through, it should leave a clear gap that remains open. Leave to cool while you make the dough.

Make the Dough

• In a large bowl, whisk together flour, sugar, baking powder, and salt.
• Add cold butter and rub into the flour with your fingertips until the mixture resembles coarse crumbs.
• Pour in the milk and mix with a spatula or dough whisk just until a soft dough forms. Do not overmix. The dough will feel soft, this is normal.
• For easier handling, chill the dough for 5–10 minutes before rolling.

Roll and Shape

• Lightly dust your work surface with about 2 Tablespoons flour.
• Turn out the dough and gently roll into a rectangle about 12 × 9 inches (30 × 23 cm).
• Roll to about 5 mm thick (just under ¼ inch). Use light, even pressure and avoid pressing too firmly, which can make the dough stick.
• Spread the cooled banana filling evenly over the surface.
• Cut into 9 even strips (about 1¼ inches / 3 cm wide).
• Roll each strip into a spiral and place cut-side up in the prepared pan.

Bake

• Bake for 20–25 minutes, until lightly golden .
• About 10 minutes before the rolls finish baking, begin preparing the brown butter glaze.

Make the Brown Butter Glaze

• Cook the butter for 3–4 minutes until golden brown and fragrant. You will see small brown specks at the bottom of the pan. Watch carefully so it does not burn.
• Remove from heat and cool slightly.
• Add the browned butter to a bowl with the powdered sugar, milk, vanilla, and salt, and whisk until smooth and spreadable.

Glaze the rolls

• Remove the rolls from the oven and glaze in the pan within 3–5 minutes while still hot. This allows the glaze to melt lightly into the tops and helps keep the rolls soft.
• Drizzle for visible swirls, or spread fully to cover the tops.

Storage

• Store covered at room temperature for up to 1 day.
• Refrigerate for up to 3 days.
• Warm slightly before serving for the softest texture.