In a large bowl add the egg yolks, sugar, and cornstarch and whisk to combine, then whisk another minute or so.

Whisk the Sugar, Yolks and Cornstarch

In a medium saucepan over low-medium heat cook the half and half, salt, and espresso powder.

Warm the Half and Half

Step 2

Once the cream mixture is warmed gently and slowly add a little bit to the egg mixture and immediately whisk to combine.

Combine

Step 3

Add all of the liquid back to the pot. Then cook over low-medium heat whisking constantly for another few minutes. Then, whisk in the cold cubed butter to help cool the mixture and stop the cooking process. Next, add the vanilla paste,

Warm the Mixture

Step 4

Place the container in the refrigerator to chill and set for at least three hours

Chill Pastry Cream

Step 6