In a large bowl or resealable bag, whisk together the white vinegar, brown sugar, salt, garlic powder, and granulated sugar.
Add the chicken and turn to coat. Refrigerate and marinate for at least 30 minutes or up to 4 hours.
Preheat the grill to medium-high heat, about 400°F. Lightly oil the grill grates to prevent sticking.
Remove the chicken from the marinade and discard the remaining marinade.
Grill the chicken for 3–5 minutes per side, or until the internal temperature reaches 165°F.
Transfer the chicken to a clean plate and let it rest for 5 minutes.
Lightly toast the buns cut-side down on the grill for a few seconds, or warm them in the microwave for about 30 seconds.
Spread your desired condiment on the buns.
Top each bottom bun with lettuce, tomato, grilled chicken, 1 slice of Colby Jack cheese, and 2 slices of bacon.
Add the top buns and serve immediately.
Notes
Store leftover grilled chicken in an airtight container in the refrigerator for up to 5 days. Assemble the sandwiches just before serving.Mayonnaise or barbecue sauce both work well as the sandwich condiment.For food safety, discard the marinade after removing the raw chicken.