In a large mixing bowl, combine the flour, granulated sugar, yeast, and salt. Mix well.
In a separate bowl, whisk together the warm milk, melted butter, egg, and vanilla extract. Pour this mixture into the dry ingredients and stir until a dough forms.
Knead the dough on a floured surface for about 5 minutes until smooth and elastic. Place the dough in a greased bowl, cover with a clean kitchen towel, and let it rise in a warm place for about 1 hour or until doubled in size.
Preheat your oven to 350°F (175°C).
Once the dough has risen, roll it out on a floured surface into a rectangle about 1/4 inch thick.
In a small bowl, mix together the brown sugar and cinnamon. Sprinkle this mixture evenly over the rolled-out dough. Then, sprinkle the chocolate chips on top.
Starting from one long side, carefully roll the dough into a tight log. Pinch the seams to seal.
Cut the log into 12 equal slices and place them in a greased baking dish. Cover and let them rise for another 30 minutes.
Bake in the preheated oven for 20-25 minutes or until golden brown.
Once baked, let the rolls cool slightly before drizzling with blue frosting. Optionally, dust with powdered sugar before serving.