In a small saucepan, whisk chipotles, raspberry fruit spread, water, vinegar, sugar, and spices over medium-high heat. Bring to a boil, then reduce to low and simmer until thickened, 12-15 minutes. Remove from the heat and let cool slightly. Add mixture to a blender and blend until smooth. Set aside to cool completely.

Cut the chicken thighs into 1 inch pieces and place them in a large bowl. Take ½ cup of the raspberry sauce and mix it with the chicken. Let sit at room temperature for 30 minutes.

Using metal skewers, assemble the kebabs. Alternate pieces of chicken, pepper, and onion until all ingredients are finished. Heat a gas or charcoal grill to medium-high. Grill the kebabs over direct heat for about 10-15 minutes, turning and basting every 2-3 minutes with the sauce until the chicken is cooked through and lightly charred. Serve with the remaining sauce.