to make the pastry cream,heat the half and half, 6 tablespoon of the sugar

and the salt in a saucepan over medium-high heat until simmering,stirring occasionaly to dissolve the sugar.

meanwhile,combine the egg yolks and remaining 2 tablespoons sugar in a medium bowl and whisk until the sugar has begun to dissolve and the mixture is creamy,about 15 seconds. whisk in the cornstarch until combined and the mixture is pale yellow and thick,about 30 seconds.

meanwhile the half and half mixture has reached a simmer,sloqly add it to the egg yolk mixture to temper,whisking constantly.Return. the mixture to the saucepan,scraping the bowl with a rubber spatula.Return to a simmer over medium heat,whisking constantly,until a few bubbles burst on the surface and the mixture is thickened and glossy,about 30 seconds.Off the heat,whisk in the butter and vanilla.Strain the pastry cream through a fine mesh seive set over a medium bowl.Press plastic wrap directly on the surface to prevent a skin from forming and refridgerate until cold and set,at least 3 hours up to 2 days.

To make the cookies,preheat the oven to 375°F.Line two baking sheets with parchment paper or silicone baking mats. Fit a pastry bag with a wide round tip. Combine the butter and sugar in the bowl of an electric mixer and beat on.medium-high speed until light and fluffy,about 2 minutes.Blend in the eggs one at a time,beating well after each addition.Blend in the vanilla.In a medium bowl combine the flour,baking powder and salt,whisk to combine.With the mixer on low speed,add the dry ingreients to the bowl,alternaing with the milk,and beatingeach addition just until incorporated.

Transfer the batter to the piping bag. Pipe 1 1/2-2 inch circles onto the prepared baking sheets,spacing an inch apart. Bake 8-10 minutes,until yhe cookies are set. ( They should not brown).Transfer to a wire rack to cool completley.Repeat with remaining batter as necessary.

Once all cookies have cooled,match them up in pairs by size.

To make the ganache,,place the chopped chocolate into a small heatproof bowl.Bring the heavy cream to a simmer in a small saucepan.pour the cream.over the chocolate let stand about 1-2 minutes.Whisk in a small circular motion until the chocolate is completly blended and ganache is smooth. Dip the rounded side of one cookie of each pair in the ganache and coat with an even layer.Return to the cooling rack flat side down,and let the ganache set before proceding,

Transfer the pastry cream to another piping bag fitted with a smaller plain round tip.Pipea dollop of pastry ceam onto the flat side of the plain cookie of each pair.Press the flat side of the other cookieto the pastry cream,sandwhiching the two together. keep refridgerated in an airtight container for up to 2 days.