Preheat the oven to 400 degrees F (200 degrees C).
Cut each sheet of Pastry Dough (1 box) into nine squares. Cut each corner of the square about one inch towards the middle.
In a saucepan, combine Rhubarb (1 stalk), Fresh Strawberry (1 cup), Granulated Sugar (8 tablespoon), Lemon Juice (1/3 cup), Ground Cinnamon (1 teaspoon), and Corn Starch (2 tablespoon) over medium heat and stir until the juices render and mixture thickens.
Whip Cream Cheese (4 ounce) with Ricotta Cheese (1/2 cup), Whole Milk (1/2 cup), Salt (1 pinch), and Granulated Sugar (2 tablespoon) until smooth.
Scoop out about 2 tablespoons of the ricotta cream cheese mixture and place in the middle of each of the dough squares. Scoop about one tablespoon of the rhubarb strawberry mixture on top of the cream cheese.
Take one corner of the dough and fold over towards the center and continue with each of the four sections until it looks like a pinwheel.
Whisk Egg (1) and brush over the top of the dough. Bake for 12 to 15 minutes. Let cool for about 10 minutes before eating.