Craquelin:

1) Combine flour, sugar, and softened butter together in a stand mixer. Paddle together on medium for 2-3 minutes until a cohesive sticky dough/paste forms.

2) Dump dough out onto a piece of parchment paper and place another piece of parchment on top of it. Roll the craquelin out to a 1/4 thick sheet and let chill in the fridge for at least 1 hour.

Creme Mousseline: A combination of creme patisserie, cookie butter, and butter

1) Combine butter and cookie butter in a heatproof bowl.

2) To make the creme patisserie, whisk together half of the sugar, cornstarch, and egg yolks in small bowl. Then, heat the milk and rest of the sugar in a saucepan on low.

3) Once the milk is steaming, pour 1/3 of the milk over the egg yolk mixture and whisk vigorously until the two have fully combined. Pour the egg mixture into the saucepan with the rest of the milk and continue to whisk vigorously while heating the mixture on medium low. This is a process called tempering.

4) Once the custard has thickened and is boiling with large bubbles (180ºF), heat for another 2 minutes before taking off the stove.

5) Pour the now finished creme patisserie on top of the cookie butter and butter. Whisk together until the butter is fully melted (the mixture will look very split).

6) Pour the split mixture into a blender or stand mixer fitted with a paddle attachment and  blend/beat on high for 2-3 minutes until a smooth mixture forms.* **

7) Cover the top directly with plastic wrap and chill in the in the fridge for at least 3 hours or preferably overnight. When ready to use, whip in a stand mixer until glossy and stiff.

Pate a Choux:

1) Preheat an oven to 400ºF. Line a baking sheet with parchment or a silpat baking mat.

1) Heat the milk, water, sugar, salt, and butter together in a saucepan. Once the butter has melted and the mixture has come to a boil, dump in the flour and mix vigorously with a wooden spoon until one mass of a pasty dough has formed. 

2) Transfer into the bowl of a stand mixer fitted with a paddle attachment and let cool for 5 minutes.

3) Once slightly cooled, mix on medium to let any steam out of the mixture. Then pour in the first egg and let fully combine, repeat with the second egg.

4) Beat the third egg in a separate bowl and add just enough (it could be none) to reach proper consistency. You want the choux dough to form a V that only drops off the paddle of your stand mixer when hit against the side of the bowl. I explain this more above.

5) Scoop the dough into a pastry bag fitted with a round tip and pipe 1.5 inch mounds onto a baking sheet lined with parchment or a silpat. Using a tablespoon scoop, cut 1 inch circles of the craquelin and top each mound of choux with a craquelin hat.

6) Bake at 400ºF for 15 minutes (DO NOT OPEN THE OVEN DOOR). Lower the oven temperature to 350º with the choux buns still in the oven. Bake for another fifteen minutes until golden brown all the way around. Remove from the oven and let cool completely.

Assembly:

1) Fill a piping bag fitted with a round top with the rewhipped creme mousseline. Insert the piping tip into the bottom of each choux bun and fill until the bun feels heavier and your piping bag is resisting you piping anymore.

2) Eat the day of and enjoy!