Preheat the oven to 350°F. Line a 9 x 13 pan with parchment paper or spray with non-stick baking spray.
Wash and dry the fruit. Chop the rhubarb and peaches; set aside.
In a food processor, mix shortbread crust ingredients. Press the crust into the pan. Bake for 15 minutes and remove from the oven.
While the crust is baking, using an electric mixer, beat together the eggs, sugar, flour, salt, cinnamon, and vanilla. Stir in the rhubarb and peaches. Pour the filling mixture onto the hot crust and evenly spread.
Bake the bars for 45 minutes. Remove the bars from the oven.
Cool before cutting and serving. Store leftovers in the refrigerator in an airtight container.