Preheat oven to 400 degrees.

Line baking sheet with parchment paper or Silpat.

In the bowl of a stand mixer, combine sugar and softened cream cheese. Beat until smooth.

Add egg yolks, ricotta cheese, vanilla extract, salt and lemon zest and mix until well combined.

On a lightly floured surface, gently roll puff pastry sheet out to smooth the creases.

Using a sharp knife, divide puff pastry into four squares.

Spoon cream cheese filling onto each puff pastry square, dividing filling evenly between squares.

Brush edges of puff pastry with egg wash and fold two corners in, making sure they over lap.

Brush top of puff pastry with egg was and bake at for 18-20 minutes until golden brown.