Preheat the oven to 350 degrees and prepare a cookie sheet lined with parchment.
In a medium bowl, whisk together flour, baking soda and salt. Set aside.
In a stand mixer fitted with a paddle attachment, combine melted butter and sugar. Mix until combined.
Add cocoa powder. Mix until combined.
Add eggs and vanilla extract. Mix until combined.
Slowly add flour mixture and mix until just combined.
Slowly add in coffee. Mix until combined.
Stir in chocolate chips and M&M's.
Use a medium ice cream scoop to scoop dough balls and place them in the fridge for 15 minutes.
Place dough balls on baking sheet, 2 inches apart, and bake for 13-16 minutes.
Take cookies out of the oven and allow them to cool on the cookie sheet.
Melt chocolate and place in a piping bag with the tip cut off.
Drizzle chocolate over cookies and set aside to dry.