Wash and dry the plums and raspberries. Pit plums and cut into 1/4 inch slices.
Make the dough for the galette or use a store bought single pie shell. For this recipe I used my Simple All Butter Pie Crust. Place parchment paper down on a hard surface. If using homemade pie crust, roll out the dough directly on the parchment paper. Roll the dough into a 13 inch circle, 1/8 inch thick. If using a store bought pie shell place the pie shell directly on the parchment paper.
In a small bowl, mix the flour, 1/4 cup sugar and cinnamon. Sprinkle mixutre evenly over the pie shell, leaving a 1-inch border.
In a mixing bowl, add plums, raspberries, lemon juice and orange zest. Toss gently. Arrange the plum slices on top, overlapping them in a circle, leaving the last layer about 2 inches from the edge. Add the raspberries.
Dot the fruit with butter. Add remaining 1/3 cup sugar and pour over the fruit.
Fold the edges of the pie shell over the the fruit. Create pleats and work your way around the shell in a circular motion. If the shell tears, patch it up by pinching it together.
Beat an egg. Use a silicone brush and brush the edge of the galette. Add turbinado sugar to the top of the egg washed edge. Place baking sheet in the refrigerator for about 15-20 minutes.
Preheat oven to 350 degrees. Set oven rack to the middle position.
Bake for about 1 hour, or until the plums are tender, the fruit is bubbling and the crust is golden brown. ( It is normal for some of the juices to leak from the galette onto the pan. These juices may burn. Once the galette is cooled just scrape away any of the burnt juices from the galette.) Once done, transfer the pan to a rack and let cool.
Once the galette is cooled and the juices have set, transfer the galette to a dish or cutting board. Cut slices, serve warm or at room temperature. Add a scoop of your favorite vanilla ice cream if desired.
Enjoy!