Slice peaches in half and remove the pit. Brush the cut side of the peaches with vegetable oil and place flesh side down on a hot grill. Grill for about 5 minutes. Brush other side of peaches with the vegetable oil and flip peaches.
Meanwhile, combine brown sugar with the cinnamon and sprinkle on top of the peaches while they are on the grill. Grill for about 4 more minutes and then remove from heat.
Let stand.
Remove skin and chop peaches into small cubes.
Place a Layer of peaches on the bottom of a parfait glass, and then add a layer of tapioca pudding, repeat ending with peaches on the top.
Sprinkle top of parfait with some cinnamon. Enjoy!