Place hot dogs in buns in 9×13 inch baking dish.
Top each hot dog with 1 Tbsp. ranch dressing and 1 Tbsp. shredded cheddar cheese.
Cover with foil and bake at 350 degrees 15-20 minutes.
Remove from oven; top with 1-2 Tbsp. buffalo mayo, ½ Tbsp. blue cheese, and sliced green onions.