In a medium saucepan over medium heat, melt the unsalted butter while stirring frequently until golden brown.

In a large mixing bowl, combine the brown sugar and granulated sugar, then add the browned butter, egg, egg yolk, and vanilla extract.

In a separate bowl, whisk together the flour, baking soda, salt, and coffee granules until well combined.

Gradually incorporate the dry mixture into the wet ingredients, stirring gently until just combined.

Carefully fold in the toffee bits and chocolate chips until evenly distributed.

Cover the dough with plastic wrap and refrigerate for 30 minutes to 1 hour.

Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

Scoop the chilled dough onto the prepared baking sheet, spacing each mound 2 inches apart.

Bake in the preheated oven for 10-12 minutes, until edges are lightly golden.

Allow cookies to cool on the baking sheet for about 5 minutes before transferring to a wire rack.