Place butter in a saucepan over medium-low heat and gently brown the butter, swirling the pan occasionally. It'll slowly start to bubble and boil and eventually start to brown at the bottom of the pan. Take the pan off the heat after you start to notice the brown flecks at the bottom and cool for about 5 minutes.

Meanwhile, place both sugars into a medium mixing bowl. Pour in the browned butter and all the brown bits from the bottom. Stir the sugars and butter together until thoroughly combined. Add the vanilla and stir to combine. Add the the egg and stir until the mixture is thoroughly combined, smooth and glossy. Now add the flour, baking soda and salt and stir just until combined; a few floury bits are okay. Pour in the chocolate chips and stir them through until they're evenly distributed and all the flour bits are gone.

Using a 1.5 tablespoon-cookie scoop, scoop out the dough and place onto a baking tray lined with baking paper. These cookies stay in the shape you put them in, basically, so flatten them gently if you like (otherwise, they'll stay in a mound shape). Bake for 7-9 minutes (mine were perfect at 8 minutes), until just set in the middle and slightly golden at the edges. Do not overbake at all, or you'll lose that beautiful soft texture.

Cool on the tray for 5 minutes, then transfer the cookies to a wire rack.

Store in an airtight container for a couple of days, they should stay nice and soft.