In a medium bowl, mix all peach glaze ingredients until smooth. Set aside.
Pat the chicken dry. Combine salt, black pepper, and chili powder, then season the chicken evenly.
Heat olive oil in a large nonstick skillet over medium heat. Add chicken and cook for 5 minutes. Flip, reduce heat to medium-low, and cook another 5 minutes until internal temperature reaches 165°F. Remove and tent to keep warm.
Increase heat to medium and add jalapeños to the skillet. Cook for 3 minutes, then add sliced peaches and cook 3 minutes more until softened.
Pour the glaze into the skillet, stirring to coat peaches and jalapeños evenly.
Return chicken to the skillet, spoon glaze over the top, and cook 1–2 minutes until heated through. Serve warm.