Preheat your oven to 200 degrees centigrade (180 degrees Centigrade fan)
Heat a 15cm/6 in cast iron skillet over a high heat. Add the butter and melt, stirring frequently until it’s giving off a delicious nutty aroma and has little brown flecks appearing at the bottom. Remove the skillet from the heat and transfer the burnt butter to a small bowl to cool for 5 minutes.
Add the sugar, egg and vanilla to the bowl and stir through with a spoon or spatula. Add the flour, salt, baking powder and bicarb and stir to combine, then add two-thirds of the chocolate chips to the dough and stir until evenly distributed. Transfer the dough to the skillet and press it out to an even layer, then sprinkle the remaining chocolate chips on top.
Bake in the oven for 10 minutes.
Remove from the oven and let cool for 5-10 minutes, then sprinkle with flaky sea salt before
plopping a generous scoop of ice cream into the middle and serve.