In a large saucepan whisk together the egg yolks, the granulated sugar and the 3 tablespoons of flour. It should be a smooth mixture. Hold this aside.
In a separate small saucepan heat the half & half over medium heat, stirring it frequently just until it comes to a simmer.
Slowly (so as not to cook the egg) pour half of the hot half & half over the egg mixture, whisking as you do. Whisk until the mixture is smooth. Slowly pour in the rest of the half & half and whisk it in. Place the large saucepan with this mixture over medium heat and whisk it constantly: as the mixture heats up it will thicken. This can take 3-6 minutes depending on your burner.
Once it has thickened whisk and cook it 2 minutes longer and then remove the pan from the heat.
Stir 1 tablespoon of lemon juice, the vanilla extract and 2 tablespoons of lemon zest into this cream until it's smooth.
Let the pastry cream cool to room temperature. Press a piece of plastic wrap to the surface of the cream and refrigerate it until it's cold - about 1 hour.
Make the choux pastry dough:
Preheat the oven to 425° F. Have ready a large baking sheet lined with parchment paper.
Heat the butter, water and salt In a medium sauce pan over medium-high heat until the water comes to a boil and the butter is melted. Remove the pan from the heat.
Stir in the remaining 1¼ cups of flour until no dry flour remains. Return the pan to the burner over medium heat.
Stir the flour mixture constantly: it will quickly pull away from the sides and form a sticky lump of dough. Keep stirring the dough over medium heat for about 3-4 minutes - as the moisture leaves the dough the bottom of the pan will get covered by a film. Don't worry about this or try to scrape it up.
Transfer the dough to the bowl of a stand mixer with a paddle attachment. Mix the dough on low for 3-4 minutes to help it cool down. The dough needs to be cool enough that you can touch it.
Beat in one egg at a time, mixing thoroughly and scraping the sides of the bowl before adding the next. Once all of the eggs are in, mix in the tablespoon of lemon juice and the 2 tablespoons of zest.
Make the puff shells:
Use a medium 2-tablespoon sized cookie scoop to scoop balls of dough onto the prepared baking sheet, spacing them about 2 inches apart.
Place the sheet in the oven and bake the puff shells for 10 minutes. After 10 minutes reduce the oven temperature to 350° F (without opening the door.) Bake the puffs for another 15-20 minutes: they should be lightly browned on top and the tops should feel sturdy. (Taking them out too early will cause the shells to collapse.)
Move the sheet of puff shells to a cooling rack and let them sit for 5 minutes - they should be cool enough to handle at this point.
Use a sharp knife to slice the puffs in half to create tops and bottoms. Allow the tops and bottoms to cool completely.
Assemble the puffs:
When the pastry cream is chilled, use a spoon or a pastry bag fitted with tip that has a large opening to fill each puff bottom with about a tablespoon of cream. Place the tops on all the puffs and then dust them with the confectioner's sugar.
Serve the puffs immediately or store them covered in the fridge until you need them. Leftover puffs can be kept covered and refrigerated for about 2 days.
Makes about 23 cream puffs.
Notes
Tips:
The Pastry Cream recipe is adapted from the recipe in The Dessert Bible by Christopher Kimball.
The pastry cream is not difficult to make as long as you remember to add the heated half & half very slowly to the egg mixture. This allows the mixtures to combine smoothly with no cooked bits of egg. It is a deliciously smooth and creamy filling for the puffs.
After the puffs come out of the oven pierce the tops just a little with the tip of a sharp paring knife. This piercing allows steam to escape and helps the puffs to stay puffy. Even with this, they will deflate a little, so don't panic. They are still a delicious vehicle for that pastry cream!