01 - Preheat the oven to 400°F. Line a baking tray with parchment paper.
02 - Roll out the puff pastry on a lightly floured surface and cut into 12 equal rectangles. Place the rectangles on the prepared tray, sprinkle with granulated sugar, and cover with another sheet of parchment paper topped with a second baking tray to prevent excessive puffing.
03 - Bake for 15 to 20 minutes until crisp and golden brown. Transfer to a wire rack and cool completely.
04 - In a mixing bowl, whisk the ricotta until smooth. Add the powdered sugar, lemon zest, lemon juice, and vanilla extract, mixing thoroughly until well combined.
05 - In a separate bowl, whip the heavy cream to stiff peaks. Gently fold the whipped cream into the ricotta mixture until fully incorporated. Refrigerate until ready to assemble.
06 - Spread or pipe the lemon ricotta cream evenly onto six pastry rectangles. Top each with a second pastry rectangle to form six two-layer servings.
07 - Dust the top layer of each mille feuille generously with powdered sugar and garnish with fresh lemon zest. Serve immediately for the best texture.