Preheat oven to 425°F. Season chicken evenly with salt and place skin sides down, in a large oven safe skillet.
Place skillet on stove, and cook over medium-high until skin is deeply golden brown, crispy, and easily releases from pan, about 15 minutes. Flip chicken and cook until lightly browned, about 2 minutes. Transfer chicken to a plate. Reserve drippings in skillet.
Add garlic and ginger to skillet; cook over medium, stirring constantly until fragrant, about 30 seconds. Whisk in broth, maple syrup, miso, and soy sauce, scraping to dissolve any browned bits. Bring to a boil over medium, whisking often, for 1 minute. Whisk together cornstarch and water in a small bowl. Whisk into sauce mixture, and cook until just thickened, about 30 seconds. Remove from heat and nestle chicken, skin side up, into broth mixture.
Bake the chicken until a thermometer inserted into the thickest part of the thigh registers 170°F, about 8 minutes.
Remove from oven and stir in vinegar. Garnish with scallions and sesame seeds.
