Preheat oven to 400F. Line a large baking tray with parchment paper.
Gently roll out the thawed puff pastry sheet on a floured surface to remove any kinks from the packaging.
Slice into 10-12 squares, or 8 rectangles.
Score the edges of each puff pastry to help you press in the centers after baking.
Brush each with the beaten egg, then bake 18-20 minutes, rotating the pan halfway through baking, until a deep golden brown and puffed up.
If needed, use a small, serrated knife to slice along the scored edges then gently press in the centers with your fingers.
Spoon a dollop of strawberry jam into the center of each.
In the bowl of a stand mixer, combine the heavy whipping cream, sugar, and vanilla paste. Beat on medium high speed for 5-6 minutes, until fluffy. Transfer to a piping bag.
Pipe the whipped cream onto the cooled pastries, then garnish with the sliced fresh strawberries to enjoy!
