Preheat your oven to 400°F (200°C). In a medium mixing bowl, combine softened cream cheese, powdered sugar, vanilla extract, and heavy cream. Beat with an electric mixer until smooth and fluffy, approximately 2-3 minutes.

In a separate bowl, gently toss fresh raspberries with granulated sugar and cornstarch. Let the mixture sit for 5 minutes.

Unfold thawed puff pastry sheets on a lightly floured surface. Cut each sheet into 6 rectangles, creating 12 pieces total.

Place 2 tablespoons of cream mixture on one half of each pastry rectangle, add 4-5 raspberries on top, fold the pastry over the filling and press edges firmly with a fork to seal.

Transfer sealed croissants to parchment-lined baking sheets, brush tops with beaten egg, cut 2-3 small slits on top for steam vents, and bake for 18-22 minutes until puffed and golden brown.

Remove from oven and cool on baking sheets for 5 minutes before transferring to a wire rack.