Coat every inch of the chicken breasts in oil and place them in the slow cooker.
Season with salt and pepper.
In a bowl or measuring cup, mix the salsa, chipotle chili powder, and brown sugar. Stir to combine.
Pour salsa mixture over the chicken breasts and turn the slow cooker on low for 3-4 hours.
At the three-hour mark, check to see if the breasts are shreddable. If they are not, leave them in the slow cooker for another hour.
If they are ready to shred, use two forks to pull them completely apart.
Keep the shredded chicken breasts and juices in the slow cooker on low for an extra hour to soak up all the flavorful juice.
Serve immediately or turn the slow cooker to “keep warm” for up to two hours.
Notes
If making a large batch be sure that your slow cooker is large enough and note that it might take longer to cook.
If you don’t want to use chipotle chili powder you can substitute with smoked paprika. It will not have the same depth of flavor, but it is still tasty.