Line a pie plate or baking dish with parchment paper and spray with non-stick cooking spray. Set aside.
To the bowl of a stand mixer, add the milk, butter, sugar, yeast, egg, flour, cocoa powder, salt, chocolate chips, and food coloring. Attach the dough hook and mix for 5-6 minutes until the dough is smooth and elastic. If you want a more intense red color, add a few more drops of food coloring as the dough comes together. (If the dough is too sticky, add more flour 1 tablespoon at a time.)
Turn the dough out onto a floured surface. Roll it out into a rectangle about 12 x 18 inches.
In a medium bowl, mix together the softened butter, sugar, cinnamon, and nutmeg until combined into a paste. Spread the paste over the dough, leaving a 1-inch border all the way around the edge.
Starting on one of the long edges, roll the dough up into a log as tightly as possible. Pinch the long seam together. Cut the dough log into 12 even slices. (Sometimes, I get up to 15 rolls.)
Place the rolls into the prepared pan with the cut sides facing up. They will be nestled close together. Let them rest for 40 minutes to allow the dough to rise.
Preheat the oven to 350 degrees F. Bake the rolls for 25 to 30 minutes or until the tops just begin to brown.
Remove from the oven and allow to cool on a wire rack while you make the glaze.
In a medium mixing bowl, whisk together the powdered sugar, milk, and vanilla until smooth. Drizzle the glaze over the sweet rolls. Serve warm.
Notes
If you don't have a stand mixer, mix the dough ingredients as instructed with a hand mixer. Then, turn the dough out onto a floured worked surface and knead by hand for 4-6 minutes.