Pistachio & chocolate sandwich cookies

A few weeks ago, the Charentes Poitou Butter PDO contacted me to create a recipe for Father's Day. So I embarked on a recipe with flavors that greatly please mine: dark chocolate and pistachio sandwich cookies. It's a relatively easy recipe that requires little equipment, and it will most likely be a hit at your table on Sunday!
For these sandwich cookies, I used Grand Fermage PDO butter for cookies that are nicely crispy and chewy and a silky smooth mousseline cream.

Content creation in partnership with Charentes Poitou Butter PDO
Preparation time: 45 minutes
For 16 sandwich cookies:

The cookies:

230g of unsalted Charentes-Poitou PDO butter
220g of muscovado or brown sugar
230g of granulated sugar
2 large eggs
2 teaspoons of vanilla extract
390g of all-purpose flour
1 teaspoon of baking powder
1 pinch of salt
300g of dark chocolate chips
150g of whole pistachios

Mix the softened butter with the sugars.

Then add the eggs and vanilla.

Incorporate the flour, baking powder, and salt, and mix until you have a homogeneous dough. Finally, add the chocolate chips and pistachios.

Form balls of 50g of dough, place them on a baking sheet lined with parchment paper and put them in the freezer for at least 30 minutes (you can leave them there for several hours or days).

Preheat the oven to 175°C, place the cookie dough balls on a baking sheet lined with parchment paper, spacing them sufficiently apart (the cookies will spread during baking). Bake the cookies for 13 minutes. Once out of the oven, let them cool on the sheet.

The pistachio cream:

1 egg
60g of sugar
35g of cornstarch
125g of milk
120g of cream
25g of butter (1)
75g of pistachio puree
100g of butter (2)
Some crunchy pearls or chocolate chips

Mix the milk and cream in a saucepan, and bring the mixture to a boil.
In parallel, whisk the egg with the sugar and cornstarch.

Pour half of the milk/cream mixture over it while mixing well, then pour everything back into the saucepan.

Cook over medium heat while whisking constantly until the cream thickens.

Off the heat, add butter (1) cut into small pieces and the pistachio puree.

When the cream is homogeneous, cover it with plastic wrap in contact and refrigerate until cool. When cold, whisk the softened butter (2), then gradually add the pistachio cream. Continue whisking for several minutes to obtain a smooth and airy cream.

Place a spoonful of cream on half of the cookies, add a few chocolate chips or crunchy pearls, then close with the other half of the cookies.

If you prepare them in advance, remember to take your sandwich cookies out of the fridge 15 to 30 minutes before eating. And enjoy!