Directions

Bring Sriracha, rice vinegar, mirin, and jelly to a boil in a small heavy saucepan over high heat. Reduce heat to medium; simmer, adjusting heat if necessary, until mixture is thick and reduced to 3/4 cup, about 10 minutes. DO AHEAD: Can be made 1 week ahead. Cover; chill. Rewarm before using.
Place drumsticks in a large bowl and season generously with salt. Cover and refrigerate for 1 hour.
Preheat oven to 450°. Whisk rice flour and cornstarch in a medium bowl. Place a wire rack on a rimmed baking sheet. Using a paper towel, pat drumsticks dry. Dredge in rice flour mixture, shaking off excess. Arrange on prepared rack.
Roast drumsticks, turning frequently, until skin is browned and crisp, 50–60 minutes. DO AHEAD: Can be made 1 day ahead. Let cool, cover, and chill. Rewarm in a 450° oven for 10–15 minutes before continuing.
Combine hot drumsticks and 1/4 cup sauce in a large bowl; toss to coat. Return drumsticks to rack and roast, turning once, until skin is crisp and sauce is beginning to brown, 8–9 minutes. Brush with additional sauce and serve remaining sauce alongside.