Preheat oven to 400 degrees F. Prepare a baking sheet with parchment paper. Unfold puff pastry on top of the parchment paper.
Cream Cheese:
To soften 8-ounce block of cream cheese, place the completely unwrapped cheese on a microwave-safe plate and microwave it on high for 15 seconds. Add 3 tablespoons of powdered sugar and mix well. Add 1 teaspoon pure vanilla extract. Spread cream cheese mixture over the pastry with a spatula.
Peaches and Blueberries:
Halve peaches, remove pit and slice into ¼ inch thick slices (as thin as you knife can do it without cutting your finger). Arrange peach slices in 4 rows (if your pastry is longer than mine, either add another row, or cut the extra dough off). Add blueberries between peach rows. Sprinkle with brown sugar.
Forming the Pastry:
Fold the sides of the rectangle to form a thicker border (alternatively you can also score the dough with a knife to keep 1 inch border). I folded the sides because I like my crust around the pie to be thick.
Baking Process:
Bake 30 minutes, or until pastry is puffed and golden brown. Remove from oven, cool for 5-10 minutes and sprinkle with powdered sugar.