Preheat the oven to 176 degrees Celsuis. Melt the butter in the microwave, and pour it in a bowl. Add in the brown sugar and granulated sugar, and whisk together.
Crack the egg over the mixture, and whisk again. Sprinkle in the baking soda, baking powder and salt, and mix. Then slowly pour in the flour and mix with a spoon. It will get thicker as you add it in, so just pour in a little at a time. Once it’s all mixed together, fold in your semi-sweet chocolate chips.
Line a baking sheet with parchment paper. Spoon cookie sized clumps of dough onto the sheet, about 10 centimetres apart. Press a few chocolate chips on the top.
Bake in the oven for 12 to 15 minutes, until done but still gooey on the inside. Let cool for 10 minutes, and sprinkle flaky salt on top.