Thaw the puff pastry according to package instructions.
Preheat the oven to 375ºF. Line 2 half sheet pans with parchment and set aside.
Beat the cream cheese with the granulated sugar until light and fluffy. Beat in the egg yolk, lemon juice, and vanilla extract or vanilla paste until well combined. The easiest method is to transfer to a piping bag or gallon zipper top bag then snip the corner off of the piping bag or zipper top bag. Otherwise, you'll need to spoon and spread the filling, which is fine, just a little more time consuming.
Unfold the puff pastry and cut each sheet into 6 rectangles. Arrange the rectangles on the prepared sheet pan, leaving ample room around each rectangle to allow it to expand as it bakes. Use a sharp knife to score a rectangle inside each dough rectangle, leaving a 1/2-inch rim. Take care not to cut all the way through the dough, just score it.
Pipe or spoon about 2 tablespoons of the cream cheese filling inside the scored rectangle. If you've spooned it, gently spread it to the edges of the inside rectangle. Arrange the berries or thinly sliced stone fruit over the cream cheese filling.
Whisk together the whole egg with a teaspoon of water. Brush over the rim around the side -but not the edges- of the pastry, and sprinkle with the raw sugar.
Bake for 20 minutes, or until the pastry is puffed, set, and deeply golden brown. Let the pastries rest on the pan for 5 minutes while you whisk together the confectioner's sugar and the milk. Drizzle over the finished pastries.
Store any leftovers in an airtight container in the refrigerator for up to 3 days. Reheat leftovers at 350ºF for 5 to 10 minutes.
If you want a pop of colour and a beautiful accent to your seasonal fruit, sprinkle lightly with fresh thyme leaves.