difference in baking boneless chicken breasts vs. bone-in?

When I poach a chicken breast I jab it with a fork to let the poaching liquid in. For the liquid I use chicken broth with a mirapoix .

If you are going to bake a boneless chicken breast would recommend brining it first. Keeps the moisture in. Absolute best way to have a tender chicken breast is to poach it.

Boneless chicken breasts will cook more quickly than bone-in, especially if they are also skinless. They will also dry out more quickly, though, so you should adapt your recipe accordingly