3 tablespoons (45 milliliters) butter, softened and cooled + more for brushing
1/3 cup (80 milliliters) brown sugar
2 teaspoons (10 milliliters) cinnamon
1/2 cup (120 milliliters) semisweet mini chocolate chips
Butter, for brushing
3/4 cup (180 milliliters) cream cheese, softened
2 tablespoons (30 milliliters) butter, softened
1/2 teaspoon (2.5 milliliters) vanilla
2 cups (470 milliliters) icing sugar
Add the yeast and one tablespoon (15 milliliters) sugar to a bowl. Add 1/4 cup (60 milliliters) water and stir. Let sit ten minutes.
Add the remaining sugar, butter, egg, and salt and mix together. Add sour cream and remaining water and mix in. Add cocoa powder and flour and mix in.
Turn onto a lightly-floured counter and knead five minutes. Form into a ball and place in a lightly-greased bowl. Cover with a tea towel and let rise three to four hours, or until doubled in size.
Remove ball to a lightly-floured counter and roll out into a 46 x 23 centimeter rectangle with the long side facing you.
To make the filling, blend together the butter, sugar, and cinnamon. Use a pastry brush to brush butter all over the surface of the dough, then spread the butter-sugar mixture on top. Sprinkle the chocolate chips on top. Tightly roll the long side of the dough away from you. Roll to make sure the seam is on the counter. Cut into nine pieces. Lightly grease a 23 centimeter skillet. Arrange the pieces in the skillet. Cover with a tea towel and let rise 90 minutes, or until doubled in size.
Bake in the oven at 375 F (190 C) for 25-30 minutes. Let cool slightly.
Meanwhile, make the frosting by beating together the cream cheese and butter. Add the vanilla and mix in. Add the icing sugar and mix to combine.
Spread frosting on top of the warm sticky buns. Serve.