Slice plums about 1/2 inch pieces. In a medium sized bowl add plums, all-purpose flour, and organic cane sugar. Gently stir together. Set set aside.
Take the dough out of the fridge. Sprinkle flour on a flat surface and place the dough over it. Roll it out just a little bit more until it is about 12-13 inches in diameter and about 1/8 inch thick. Don’t worry about it being perfect, galettes are meant to look a little ragged and rustic!
Place the dough back on the parchment lined baking sheet.
Now it’s time to arrange the plum slices on top of the dough. Starting at the center, arrange plums in overlapping concentric circles until you’ve reach about 2 3/4 inches of the edge of the dough.
Fold the edges of the dough over the plums in a free form fashion. Making your way around and creating pleats as you fold. If you want to fix any sections that maybe torn, pinch a bit fo the dough from the edge to help put it back together.
In a small bowl whisk together egg and jam. Using a pastry brush, brush the edges and pleats of the dough. Then sprinkle sugar over the top of the crust and plums.
Bake in the oven for 50-65 minutes or until the plums are tender and the crust is golden brown.
Once galette is out of the oven, allow it to cool down for a few minutes before serving. It is normal for there to be juice residue and slight burnt areas where the juice is. That is normal. You can simply scrap away those parts and enjoy the galette!