Preheat your oven to 350°F (175°C).
Line a large baking sheet with parchment paper.
In a large mixing bowl, whisk together the melted unsalted butter and granulated sugar until smooth and creamy. Add vanilla extract and mix well.
In another bowl, whisk together the all-purpose flour and salt. Gradually add the dry ingredients to the wet mixture, stirring until just combined.
Gently fold in the mini chocolate chips and broken chocolate chip cookies until evenly distributed.
Pour the cookie mixture onto the prepared baking sheet and spread evenly with a spatula.
Bake for 20-25 minutes or until edges are lightly golden. Remove and let cool completely in the pan.
Melt the semi-sweet chocolate in a microwave-safe bowl in 30-second intervals, stirring until smooth.
Pour the melted chocolate over the cooled cookie base and spread evenly with a spatula.
Place in the refrigerator for at least 30 minutes to set. Once firm, break into pieces and serve.