Preheat the oven to 400°. In a medium bowl, whisk together the brown sugar, cayenne and cinnamon. Toss the bacon in the sugar mixture.
In a medium skillet set over medium heat, cook the bacon, stirring frequently, until crisp, about 7 to 10 minutes.
Place the green beans in a medium bowl. Drain the bacon fat from the skillet; reserve the seasoned bacon. Toss the bacon fat with the green beans. Season the green beans with salt and pepper. Spread the green beans on a sheet tray and bake until tender and beginning to blister, about 15 minutes.
Transfer the beans to a serving plate, drizzle with the lemon juice and top with the reserved bacon candy and sea salt. Serve warm.