Into a mixing bowl, add Corn Starch (2 tablespoon) and Milk (1 cup). Whisk until smooth, then set aside.
Add the remaining Milk (1 cup) into a saucepan.
When milk is hot, add Unsweetened Chocolate (4 ounce). Cook over medium heat, stirring regularly, until chocolate has completely melted.
Add the Granulated Sugar (1/4 cup), Instant Coffee (1 teaspoon), and corn starch mixture. Stir until mixture thickens. Remove from the heat and set aside.
Into a saucepan, add Water (1 cup) and Butter (1/2 cup). Heat until melted together.
Add the All-Purpose Flour (1 cup) and Salt (1/4 teaspoon). Cook over medium heat, stirring constantly, for 1 minute.
Transfer the dough to the bowl of a stand mixer. Mix on low for 1 minute.
Slowly add the Egg (3). Continue mixing until smooth.
Transfer dough to a pastry bag fitted with a churro tip.
Heat Cooking Oil (to taste) to 330 degrees F (165 degrees C).
Pipe churros out into the oil. Fry until golden brown. Remove finished churros to a wire rack to drain.
Place churros into a bag with Cinnamon Sugar (to taste). Shake to coat.
Serve churros alongside chocolate dipping sauce. Enjoy!