In a medium bowl, combine raspberry preserves, extra virgin olive oil, soy sauce, apple cider vinegar, Dijon mustard, minced garlic, kosher salt, black pepper, and red pepper flakes. Whisk the mixture until well blended, creating a smooth and vibrant glaze that will coat the chicken beautifully. Set this aside to let the flavors meld while you prepare the chicken thighs.

In a small bowl, mix together kosher salt, black pepper, and chili powder. Pat the boneless, skinless chicken thighs dry with paper towels, ensuring they are ready to absorb the flavor. Rub the seasoning mixture evenly over both sides of the chicken, enhancing the flavor profile of your Jalapeno Raspberry Chicken before cooking.

Add 2 tablespoons of extra virgin olive oil to a large nonstick skillet and heat it over medium heat. Allow the oil to shimmer for about 1 minute, signaling it's ready for the chicken. This step is crucial for creating a delightful golden-brown crust on the chicken thighs while keeping them moist and flavorful during cooking.

Carefully place the seasoned chicken thighs in the skillet, ensuring they are not overcrowded. Cook for about 5 minutes, or until the bottom is nicely browned and releases easily from the pan. Flip the thighs, reduce the heat to medium-low, and continue cooking for another 5 minutes, or until the internal temperature reaches 165°F, ensuring each bite of your Jalapeno Raspberry Chicken is perfectly tender.

Once cooked through, remove the chicken thighs from the skillet and tent them with foil to keep warm. This resting step allows the juices to redistribute, ensuring every bite of your Jalapeno Raspberry Chicken remains succulent and full of flavor.

In the same skillet (don't clean it!), add sliced jalapeños to the flavorful drippings and the prepared raspberry glaze. Cook for 1-2 minutes, scraping up any browned bits from the bottom of the skillet. This step not only utilizes the pan's residual flavor but also infuses the glaze with a hint of heat from the jalapeños.

Gently fold in the fresh raspberries into the skillet, stirring carefully to coat them with the glaze without breaking their delicate texture. Cook briefly for about 1 minute, allowing the raspberries to warm through and release some of their juices while enriching the glaze for your Jalapeno Raspberry Chicken.

Return the chicken thighs to the skillet, spooning the luscious glaze over each piece. Heat for another minute, ensuring the chicken is warmed through and enveloped in savory sweetness. Serve the Jalapeno Raspberry Chicken warm, garnished with remaining fresh raspberries and a side of your choice for a delightful weeknight meal.