Preheat oven to 350-degrees F. Generously spray a bundt pan with nonstick cooking spray. If unsure of yourself, you may dust with flour, pouring out excess. With the palm of your hand, flatten each cinnamon roll out on a clean work surface to a 1/4-inch thickness. Place about 6-8 blueberries in the center of each roll and fold in half, forming a half-moon shape. The center of each cinnamon roll may stick to work surface, but simply lift up and fold over. Slightly crimp the edge together and lay these half-moons inside bundt pan. Stagger each roll very loosely.
When done with 12 rolls, place in the oven and bake 40-45 minutes, or until well browned on top. Remove from oven and let cool 10 minutes.
Meanwhile, make icing and ganache. In a large bowl, combine 2 c. powdered sugar with 1/4 cup room temperature cream cheese and 2 tablespoons milk. With a hand mixer or stand mixer, beat on low until cream cheese is incorporated, turning to medium speed to blend together well. If you need to add more milk, do so a tablespoon at a time, until just barely pourable.
For the ganache, in a small bowl, combine 1 1/2 cups chocolate chips with 1/4 cup heavy, light or half-and-half cream. Microwave on high for 1 minute, remove and stir. Microwave at 15 second intervals until it is smooth and entirely melted.
Drizzle either icing or ganache over cake and decorate as you prefer.