Brown the butter lightly in a pan over medium heat until golden, then let it cool for 5 minutes.

In a bowl, mix the cooled butter with granulated and brown sugar using a whisk for 3 minutes until combined.

Add the egg and whisk until incorporated, making sure the mixture isn’t too warm to avoid scrambling. Add the baking powder and mix again with the whisk. 

Switch to a spatula and fold in the flour until just combined.

Once the dough cools, gently mix in the chocolate chips without overmixing.

Preheat the oven to 180°C (350°F).

Divide the dough into 4 equal portions. Press one portion into each ramekin base, creating a slight well.

Add a generous spoonful of Nutella to each well, then flatten another dough portion and place it on top, sealing the edges.

Sprinkle extra chocolate chips on top and bake for 15 minutes until golden but still soft inside.

Let cool for 5-8 minutes before serving warm with ice cream.