Bloom the yeast

• Warm the milk and mix in part of the brown sugar.
• Once it reaches about 110°F, stir in the yeast and let it bloom.

Make the dough

• Mix in the eggs, melted butter, remaining brown sugar, vanilla paste and food coloring.
• Add the flour and salt, starting with part of the flour and adding more as needed until you have a soft dough.
• Knead until mostly smooth; the dough may feel tougher than usual with the food coloring, so don't keep adding flour.

Let the dough rise

• Place in an oiled bowl, cover and let rise somewhere warm until doubled in size.

Make the filling

• Mix the softened butter, brown sugar, cinnamon and finely crushed Oreos.
• Separately mix the black cocoa powder with the heavy cream until smooth, then mix it into the filling.
• Add black food coloring if you want an even darker filling.

Shape the rolls

• Punch down the risen dough and roll it into a rectangle.
• Spread the filling evenly over the dough, cut into 8 strips and roll each strip individually.
• Place the rolls into a parchment-lined 9x13-inch baking dish.

Rest and preheat

• Let the rolls rest while the oven preheats to 350°F.
• Pour the heavy cream over the rolls just before baking.

Bake

• Bake, checking earlier since ovens and roll sizes vary.
• If the tops start getting too dark before the centers are done, loosely tent with foil.
• Make sure the centers are baked through.

Make the frosting

• Beat the cream cheese and butter until fluffy.
• Mix in the powdered sugar, vanilla and optional pinch of salt.
• Taste and adjust the sweetness to your liking.

Color the frosting

• Divide the frosting into about two-thirds blue and one-third purple.
• For the deep blue, mix mostly blue with a little purple and black.
• For the purple, use purple and blue, with a tiny bit of burgundy if needed; keep adjusting until you get the shades you want.

Two-tone swirl and decorate

• Lay plastic wrap flat and pipe the blue and purple frosting in two lines side by side.
• Roll the plastic wrap into a log, twist the ends, snip one end and place it inside a piping bag.
• Pipe onto the cooled cinnamon rolls and finish with candy stars.