Preheat your oven to 350°F. If you don't have a large non-stick cookie sheet, line a baking tray with parchment paper.

In a large mixing bowl, using a hand whisk, whisk together the melted butter and both sugars until smooth and combined.

Add the egg and vanilla extract and whisk until the mixture is smooth.

Then add in the flour, baking soda, and salt. Fold everything together gently using a rubber spatula until just combined.

Fold in the chocolate chips, ensuring they are evenly distributed throughout the dough.

Cover the bowl with plastic wrap and refrigerate for at least 1 hour.

Once chilled, scoop approx 2 tablespoons of dough per cookie and place them 4 inches apart on the prepared baking tray or cookie sheet.

Bake in the preheated oven for 8-10 minutes, or until the edges are golden brown and crisp.

The cookies will look puffy when they come out but will flatten and crinkle at they cool, so make sure you don't overbake.

Leave them to cool on the tray for 20 minutes before transferring them to a wire rack. This will prevent them from breaking.