Preheat your pellet grill to 350˚F and allow it to come to temp. While waiting, mix all your filling ingredients except the peaches in a large pot on the stovetop. Allow to come to a simmer. Cook for 5 minutes, stirring and mixing. It should thicken up just a bit. Remove from the heat and allow to cool slightly.
Grab a large cast iron pan and preheat it on the pellet grill for 5 minutes with half a cup of butter. Allow the butter to melt and become hot. Mix all the ingredients for the batter in a bowl. Pour the batter directly into the cast iron pan and smooth out. Then pour your cherry filling on the batter and layer on the peach slices. Close the grill lid and cook for 40 minutes. Check it around the 35-minute mark. You want it to brown up around the edges and the batter to cook and have no wobble. Time can vary, but you should be done after about 40-45 minutes.
Once the cobbler is thoroughly cooked, remove it from the pellet grill and allow it to cool slightly. Serve with a generous scoop of vanilla ice cream.
