Make the Cookie Batter (it's more of a batter than a dough!)
In a double boiler or a microwave safe bowl, melt the chocolate and butter together. If you are using the microwave, be sure to run it at 50% power, in short bursts. Run it for 30 seconds at a time, stirring in between, with the run time going down to 20 seconds and then 10 seconds as you go.
Set the chocolate mixture aside to cool.
In a large sized bowl, beat the egg and brown sugar together, and then add the baking powder, salt, and vanilla extract.
Pour in the cooled chocolate mixture and mix until fully combined.
Stir in the cocoa powder until everything is fully combined.
Stir in the flour just until you can't see any more flour.
Add the toffee bits and chocolate chips and fold in until they are evenly distributed.
Bake
With a cookie scoop or a tablespoon, portion the batter into little mounds on your prepared baking tray. Be sure to leave about 2" of space in between, because they will spread a lot.
Bake the cookies for 11 to 12 minutes. If you are baking on a dark-colored tray or on nonstick aluminum foil, this time will probably be reduced by a few minutes, so keep an eye on them.
The cookies will still be soft in the middle when done, but will have a crisp top. The internal temperature should read around 180°F (86°C).
Store
Keep these cookies in an airtight container at room temperature.
They will keep for about a week or so. The crisp outside will soften as the days go on. You can also freeze these cookies in an airtight container.