Preheat oven to 350 degrees. In a large bowl, using an electric hand blender, mix together the butter, egg and dry cookie mix. Blend until a dough forms.
Spray a 10” cast iron skillet with nonstick spray. In a large bowl, combine all ingredients for the filling. Pour berry mixture into prepared skillet. Divide dough evenly into 6 balls of dough.
Place each dough ball into the berries then bake 30-35 minutes until the dough is golden and the berries are bubbling. Cover skillet with foil for the last 10 minutes if the cookies begin to brown too fast.
Sprinkle with powdered sugar to garnish.