In a medium bowl, combine the raspberry preserves, olive oil, soy sauce, apple cider vinegar, Dijon mustard, minced garlic, kosher salt, black pepper, and red pepper flakes. Mix until well incorporated. Set aside.

In a small bowl, combine the kosher salt, black pepper, and chili powder.

Apply the seasoning mixture evenly to the chicken thighs.

To a large nonstick skillet over medium heat, add oil. Once hot, add the seasoned chicken thighs. Depending on the size of your skillet, you may need to work in batches.

Cook the chicken for 5 minutes on one side. Flip the chicken, reduce the heat to medium-low, and cook for an additional 5 minutes, or until the chicken reaches an internal temperature of 165°F.

Remove the chicken from the skillet and transfer it to a plate. Tent with aluminum foil to keep warm.

To the skillet, add jalapeno peppers and raspberry glaze. Stir to combine, scraping up any browned bits in the pan.

Add the fresh raspberries to the skillet, gently stirring to coat the raspberries in the glaze without breaking them up too much.

Return the chicken to the skillet. Spoon the glaze over the top of the chicken and cook until the chicken is heated through again, about a minute.

Serve warm.