Prepare the Pastry Cream

1. Add the egg yolks to a medium sized bowl and gently beat them together. Set aside.
2. Add the sugar, cornstarch and milk to a large saucepan and mix until smooth.
3. Cook, stirring continuously, over medium-high heat until mixture begins to thicken and bubble.
4. Reduce heat to medium and simmer for 2 minutes. Remove from heat.
5. Add a little bit of milk mixture to the egg yolks and whisk together, then add egg mixture to milk mixture. This process ensures that you don’t scramble the egg yolks.
6. Place the pan back on the heat and bring to a light boil. Allow to boil for 2 minutes, stirring continuously.
7. Remove from heat and add butter and vanilla extract. Stir until smooth, then top with clear wrap that touches the top of the cream (it helps prevent a film from forming on top). Refrigerate until cool and ready to use.

Assemble the Napoleons

1. Remove the two sheets of puff pastry from the box and cut each set into 3 strips, for a total of 6 strips.
2. Place on a baking sheet and bake for about 13 minutes.
3. Remove them from the oven and allow to cool. Press the baked pastry down just a bit, if needed so they layers are relatively flat.
4. To finish making the pastry cream, add the heavy whipping cream and powdered sugar to a large mixer bowl and whip until stiff peaks form.
5. Gently fold the whipped cream into the pastry cream.
6. To layer everything together, place a layer of puff pastry onto a serving plate and top it with some chopped strawberries.
7. Pipe or spread some pastry cream on top of the berries, then repeat another layer of puff pastry, strawberries and pastry cream.
8. Top off the pastry with a third pastry strip on top. Repeat the layering process with the remaining puff pastry, pastry cream and strawberries.
9. To make the icing, add all ingredients to a small bowl and whisk until smooth. Spread the icing onto the top of the completed napoleons.
10. To add the whipped cream topping, add the ingredients to a large mixer bowl and whisk until stiff peaks form.
11. Pipe swirls of the whipped cream on top of the napoleons and top with a few additional chopped berries. Refrigerate until ready to serve.