Preheat your oven to 350°F (175°C) to ensure even baking.
In a large mixing bowl, whisk together the melted butter, light brown sugar, and granulated sugar until smooth. Add in the egg, egg yolks, and vanilla extract, whisking until well combined and creamy.
In a separate bowl, mix together the all-purpose flour, cornstarch, and salt. Gradually add this dry mixture to the wet ingredients, stirring until just combined. Be careful not to overmix!
Gently fold in the semi-sweet chocolate chips and toffee bits using a spatula.
Pour the cookie dough into a greased pie dish, spreading it evenly. Smooth the top for an even bake.
Place the pie dish in the preheated oven and bake for 30-35 minutes, or until the edges are golden and the center is just set.
Once baked, remove the pie from the oven and let it cool for at least 10-15 minutes before serving.