Optional: Preheat oven to 400 degrees (this is for toasting the buns if you choose. You don't have to toast the buns but it's oh so worth it!)
Pat shrimp dry and season with Old Bay.
Easy Slaw: in a medium bowl, mix half of the mayo (¼ cup) with the sugar, lime juice, scallion whites, and shredded cabbage. Season with salt and pepper to taste. Set aside.
Sweet Heat Sauce: in a small bowl, mix remainining ¼ cup mayo, honey, and hot sauce. (This yields just a mild heat. Add more hot sauce if desired to increase the spice level.)
If you want to toast the buns, spread a thin layer of butter over the inside of each side of the bun. Roast on the top rack for 5 minutes until just crispy and golden.
Heat a large pan over medium high heat and then melt one tablespoon butter. Add seasoned shrimp and cook for 2-3 minutes without moving. Flip shrimp and cook another couple of minutes until pink and no longer translucent.
Build your Po Boys by spreading a thin layer of cabbage on the bottom of your toasted roll. Add a heaping pile of cooked shrimp. Sprinkle with scallion greens and drizzle with sauce. Serve immediately.