Preheat oven to 375 degrees F. Line a baking sheet with parchment paper.
Unfold the puff pastry onto the prepared baking sheet. Cut each sheet into three equal rectangles and bake for 8-10 minutes, or until golden and puffed.
In a medium bowl, whisk together the cream, egg yolks, sugar, vanilla, and cinnamon. Set aside.
Remove the puff pastry from the oven and let cool slightly. Place one rectangle on a serving plate and top with a layer of custard. Top with a layer of sliced strawberries. Repeat with remaining pastry and custard, ending with a layer of strawberries on top.
Dust with confectioners' sugar and serve immediately.
Interesting Facts
Napoleons are a type of French pastry, also known as mille-feuille, which translates to “a thousand leaves”.
The puff pastry layers of a Napoleon are traditionally made with layers of paper-thin pastry dough that have been brushed with butter.
Napoleons can be filled with a variety of sweet fillings, including custard, whipped cream, chocolate mousse, and fresh fruits.