Heat milk, vegetable oil, & sugar in saucepan over medium heat. Set aside & cool to lukewarm. Pour milk into bowl & sprinkle yeast over it. Let sit for 1 min.
Add 4 cups of the flour to bowl & stir until combined. Cover with towel & set in a relatively warm place to rise for an hour.
Add baking powder, baking soda, salt & remaining ½ cup of flour and stir thoroughly to combine.
Melt butter in a saucepan over medium heat. Pour 1 Tbsp of melted butter each into two round baking dishes or pie plates
Pour remaining melted butter over the surface of the dough & use fingers or pastry brush to spread butter evenly.
Generously sprinkle cinnamon & sugar over the butter & top with blueberries & rainbow sprinkles.
Starting at the long end farthest from you, roll dough tightly toward you. Use both hands to roll evenly. Pinch seams together at ends.
Transfer dough to cutting board & using a sharp knife, cut dough into 1-inch slices. Place rolls into pans. Cover rolls with a towel for 20 mins, so they can rise again
Bake at 375 degrees for 16-20 mins, until rolls are turning golden around the edges.
Place blueberries in a bowl & use a fork to mash together. Add confectioners' sugar & milk & whisk until smooth.
Remove cinnamon rolls from oven & immediately pour icing over them.
These Funfetti Cinnamon Rolls are the perfect addition to a brunch party for Mother's Day or any celebration!