Set out a large salad bowl and a large skillet. Place the chopped lettuce in the salad bowl.
Set the skillet over medium-high heat. Add the chopped bacon and cook until brown and crispy. Once the bacon is crisp, stir in the scallions, vinegar, sugar, salt, black pepper, and cayenne.
Pour the hot bacon mixture over the lettuce and toss to coat. Serve warm.
You can prep the components so that you have the chopped lettuce and bacon grease dressing in separate containers for a day or so... But don't add the warm bacon dressing until you're ready to serve. When ready to enjoy, heat the dressing up in the microwave or on the stovetop for just a few seconds until warm. Then immediately pour over the greens, toss and serve!