Place the butter in heat-safe medium or large bowl. Set a fine-mesh sieve over the top of the bowl and set aside.

In a medium saucepan, heat the milk and 2 tablespoons of the sugar over medium heat.  Bring it slowly to a simmer, then remove from the heat.

Separately, in a medium mixing bowl, whisk together the remaining sugar, honey, and cornstarch.  Whisk in the eggs yolks until smooth.

Get your whisking hand ready...start whisking a SMALL amount of the hot milk into the egg mixture, whisking vigorously to help incorporate it (you don't want to cook the eggs).  Continue whisking small amounts of the milk mixture into the egg mixture to slowly raise temperature of the eggs. 

Once all the milk is incorporated, transfer the milk/egg mixture back to your saucepan. 

Place the saucepan back on the stove and cook over medium-low heat, stirring continuously.  Heat the custard and keep stirring until it thickens (enough to really coat the back of a spoon).  Don't be tempted to turn the heat up, just be patient and keep whisking until slow, large bubbles start to pop on the surface.  Whisk continuously for one more minute, then remove from the heat.

Pour the hot pastry cream through the mesh sieve into the bowl with the butter, and add the vanilla and salt (start light with the salt, then add more).

Stir until smooth and then cover with a piece of plastic wrap pressed directly onto to the surface of the pastry cream (to prevent a skin forming).  Refrigerate until it's cool and thick, at least 2 hours or overnight.