I picked one up for $4.59.
The new bun is similar to the brioche bun that it replaces and can also be found on Jack's sirloin burgers as well as the Homestyle Ranch Chicken Club. In a marked departure from most fast food buns, the signature bun came well-toasted on both sides. Picking it up, there's a satisfying crisp, thin crust to it that reminded me of fresh-baked bread and is something I haven't really ever encountered in a burger (fast food or otherwise). Inside was a squishy soft, moist, and sweet crumb that's very brioche-like. If you liked the previous (and short-lived) brioche bun, this one is even better.
The provolone proffered a very mild creaminess.
The creamy tomato sauce tasted like slightly roasted tomato and mayo.
Nutritional Info - Jack in the Box Classic Buttery Jack (270g)
Calories - 816 (Calories from Fat - 471)
Fat - 52g (Saturated Fat - 23g)
Sodium - 1148mg
Carbs - 50g (Sugar - 12g)
Protein - 37g