Preheat a grill to medium-high heat. Grease the grates with a paper towel soaked with a small amount of vegetable oil.
Place a small pot over medium heat with the butter. Add the shallot and garlic and cook until aromatic, 1 minute. Add the chili sauce, cola and cherry preserves, season with salt and pepper and bring to a simmer. Simmer until thickened, about 10 minutes.
Toss the chicken in a bowl with the onion powder, garlic powder, vegetable oil and some salt and pepper. Grill, turning occasionally, until almost cooked through, about 8 minutes. Brush some of the sauce over the chicken and continue grilling until cooked through completely, about 2 more minutes. Serve the chicken with the remaining sauce.