In a large bowl, beat the softened cream cheese with a rubber spatula until completely smooth and no lumps remain, about 1 minute. This is crucial - cold cream cheese will tear the tortillas.

Add the buffalo sauce, ranch dressing, and garlic powder. Stir until fully combined and the mixture is a uniform orange color. Taste and add more hot sauce if you want extra kick.

Add the shredded chicken, cheddar cheese, celery if using, and green onions. Fold everything together gently but thoroughly so the chicken is evenly coated and distributed throughout.

Lay a tortilla on your work surface. Spread about 3/4 cup of the filling evenly across the entire surface, going all the way to the edges. The layer should be thin but completely opaque - too thick and the pinwheels won't hold together.

Starting from the bottom edge, roll the tortilla up as tightly as possible without squeezing the filling out. Apply gentle, even pressure. Wrap the roll tightly in plastic wrap and twist the ends to seal. Repeat with remaining tortillas.

Place the wrapped rolls on a plate and refrigerate for at least 2 hours, or up to 24 hours. This step is non-negotiable - the filling needs to firm up so you can slice clean rounds.

Unwrap one roll and place seam-side down on a cutting board. Using a sharp, thin-bladed knife, slice into 8 even rounds, about 1 inch thick. Wipe the knife clean between cuts for neat edges. Arrange on a platter and serve cold or at cool room temperature.