Make the crust

1. Preheat the oven to 350-degree F and line the bottom of a 9-inch springform pan with parchment, or lightly oil bottom and sides. Set aside.
2. In a food processor, grind the crackers until fine, then add the dates and pulse a few times. Add the remaining ingredients and process until dough is uniform and holds together when pressed. Scrape dough out of the bowl and pat evenly into the pan and a bit up the sides. Bake for 10 minutes.

Make the filling & glaze

1. Meanwhile, prepare the mango and plums as directed. In a small bowl, whisk together the starch and the water. In a separate small bowl, whisk together the fruit jam and the water. Set aside.
2. Remove the crust from the oven and let cool for a few minutes. Then arrange the fruit slices on the crust as nicely as you like. Carefully pour the water-starch mixture over the fruit. Bake for about 25 minutes.
3. After 25 minutes, remove the tart from the oven and brush the glaze over the fruit. Return tart to the oven for about 10 more minutes.
4. Let the tart cool in the pan until ready to serve. The liquid will firm as the tart cools.