Combine everything but the chicken in a blender and blend until smooth. Pour over chicken and let stand at room temperature for 15 minutes (or refrigerate for up to overnight). While the chicken marinates, preheat the oven to 425ºF and line a rimmed baking sheet with foil and rub it with a bit of avocado oil to prevent sticking.
Lay the marinated thighs onto the baking sheet, pouring any marinade over top and bake at 425ºF for 12 minutes then flip and cook another 8-10 minutes, or until cooked through (165ºF internal). Broil briefly on high to char lightly, if desired.