Preheat oven to 350 degrees.
Pit beach plums and slice peaches into a bowl, add vanilla and almond extract.
Measure sugar and starch and blend thoroughly.
Combine fruits with sugar and starch and mix until the sugar looks like wet sand.
Transfer fruit into 8” x 8” pan, then cover evenly with crisp topping.
Bake in a preheated 350 degree oven for 45 minutes to 1 hour, until juices are bubbling throughout and the crisp topping is a deep brown.