Preheat the oven to 350. Grease two cookie sheets or line with parchment paper.
Beat butter until light and fluffy, about 1 minute.
Add in brown sugar and granulated sugar. Beat until fluffy, about 1 minute.
Add in egg. Mix until combined.
Next, add in baking soda, salt, and vanilla extract. Mix until combined.
Add in all purpose flour and espresso powder. Mix until combined.
Next, add in dark chocolate chips, toffee bits, and crushed toffee candy bars. Mix until everything is combined.
Scoop dough into 2 Tbsp balls and place them evenly apart on your cookie sheets (I do 6 per cookie sheet).
Bake for 13-15 minutes or until lightly golden brown. Allow them to cool on a cookie sheet for 5 minutes (they will continue to cook/firm on the sheet) and then allow them to finish cooling on a wire wrack.
Enjoy!