Combine milk and cream in a small saucepan. Using a sharp knife, split vanilla bean in half lengthways and scrape out seeds. Add bean and seeds to milk mixture. Place over medium heat. Cook, stirring constantly, for 5 minutes or until hot (do not allow to boil). Remove saucepan from heat.
Whisk egg yolks, sugar, and cornstarch, in a heatproof bowl until well combined. Slowly pour hot milk mixture over egg yolk mixture, whisking constantly.
Return mixture to saucepan over low heat. Cook, stirring constantly, for 6 - 8 minutes, or until custard thickens and coats the back of a metal spoon.
Transfer the custard into a large bowl and place a piece of plastic wrap directly onto the custard (to prevent a film from forming). Transfer the bowl into the fridge and chill for 3 hours, or until the the custard is no longer hot.
In a medium bowl, combine all ingredients and mix with rubber spatula until smooth.
Roll out the craquelin dough to 1/8-inch in thickness. Use a cookie cutter and cut out 12 2-inch circles. Set aside.
Pâte à Choux
Preheat oven to 350F.
In a saucepan, combine the water, milk, sugar, salt, and butter. Bring to a light boil, remove from heat, and immediately add in all the flour. Quickly stir in the flour, using a rubber spatula, and return saucepan back over medium-high heat.
Continue to stir the mixture, without stopping, until the paste is smooth, about 1-2 minutes. It will pull away from the sides of the pan and leave a thin coating of cooked paste on the bottom when ready. The texture should resemble dry mashed potatoes.
Transfer the paste to a stand mixer bowl fitted with the paddle attachment. Mix on low for the choux to cool down.
While the mixer is running on medium, gradually stream in the lightly beaten eggs. Mix until well combined.
Transfer the pâte à choux to the prepared piping bag with a round tip. Pipe out 12 choux mounds onto the prepared baking sheet, leaving roughly 2 inches between each puff. If you are making choux with a craquelin top, this is when you want to add the craquelin to the choux mounds.
Place the baking sheet in the oven and immediately bake choux puffs for 35 minutes. Rotate the baking sheet and turn down the oven to 325F, then bake for 10 minutes more until choux are deeply golden. Remove from oven and set on cooling rack to cool.
Trim the tops off of the cooled choux pastry with a sharp serrated knife. Set the tops aside.
Transfer the chilled vanilla custard into a piping bag fitted with a large round piping tip. Alternatively, you can use a spoon to to fill the puffs. Pipe the custard into the puffs until it reaches the brim. Use the back of a spoon or offset spatula to smooth out the custard if necessary.
Sprinkle granulated sugar on top of the custard of the filled puff. Using a torch, brûlée the top of the puff until the sugar is deeply golden brown. The sugar should be bubbling and caramelizing. Allow the sugar to cool and set.
Crème Brûlée Cream Puffs by Amy of Constellation Inspiration