While the dough rises, make the chocolate cinnamon roll filling.

In a medium sized bowl, mix together 2/3 cup packed light brown sugar, 2 Tablespoons of black cocoa, and 1 teaspoon of ground cinnamon, then set aside.

Preheat your oven to 200 F / 95 C.

In a large bowl or the bowl of a stand mixer, combine 3 1/4 cups of flour, 1/2 cup unsweetened cocoa powder, 1 packet instant yeast (or about 2 teaspoons), 1 tsp instant coffee and 1 tsp salt.

In a separate bowl, add 1 cup milk, 1/2 cup granulated sugar, and 1/4 cup softened butter into a microwave safe bowl.

Heat on high power for 60-90 seconds, until the mixture is warm to the touch. Stir to combine the ingredients.

Slowly add the warm milk mixture into the flour mixture and mix on medium speed with a dough hook until the dough comes together.

Add in one large egg and mix on a low speed until a sticky dough ball forms.

Continue to mix on a medium speed for 2-3 minutes, until the dough becomes more elastic.

As the dough mixes, add additional flour 1 Tbsp at a time until the dough begins to leave the sides of the bowl. My favorite way to know if my dough is ready is to poke it with my finger. It should feel tacky but not sticky. As you pull your finger away, there should be no residue on your finger.

Cover your bowl with plastic wrap and let the dough to rest for 15 minutes. This allows the gluten in the dough to relax a bit, which will make it easier to roll out. The plastic wrap should fog up a bit from the warmth of the dough.

Generously flour your counter and roll your dough ball into a large rectangle 12 inches x 18 inches. It should be about 1/2 cm thick. 

Spread 1/4 cup of softened butter over the dough, leaving 1 inch on the long side of the rectangle uncovered. This will make it easier to seal the log once it's rolled.

Sprinkle the chocolate cinnamon roll filling (instructions above) evenly over the buttered area, and pat down with the back of a spoon or spatula.

Tightly roll the dough horizontally, toward the uncovered strip.

Cut dough log into 9 equal pieces with dental floss (you can cut it into more pieces if you want smaller/shorter cinnamon rolls), and place in a greased square pan (mine is 8in x 8in).

Turn the oven off! I REPEAT, TURN THE OVEN OFF.

Cover the cinnamon roll pan with foil and place in a the oven for 30 minutes (or until the cinnamon rolls have risen).

Remove the pan from the oven and take off the tinfoil. Turn the oven back on, and heat to 350 F / 175 C.

Once the oven has preheated to 350 F / 175 C, bake for 26-32 minutes. I find the sweet spot in my oven is about 28 minutes. Bake time can vary based on how gooey or baked through you like your cinnamon rolls.

To make the cinnamon roll frosting, place 1 Tbsp of unsalted butter, 2/3 cup milk or dark chocolate chips, and 3 Tbsp of whole milk in a medium sized bowl.

Heat in the microwave on a medium-high heat (power level 7) for 60 seconds.

Stir the mixture together with a spoon or whisk, making sure all the chocolate is melted.

Add in 1 cup of powdered sugar and 1 tsp vanilla extract. Mix together until smooth.

Let the cinnamon rolls cool for 5-10 minutes, then drizzle the chocolate glaze over the cinnamon rolls. Serve warm.