This is the vanilla custard filling used for many cakes as well as Boston Cream Pie, Chocolate Éclairs, Fresh Fruit Tart, and countless other desserts. You can add 1 to 2 tablespoons liqueur to any variation of this custard along with the vanilla, if desired. For a lighter but richer filling, fold up to ¾ cup Whipped Cream into this or any of the variations that follows.

Whisk together in a medium heatproof bowl until smooth:

Bring to a simmer in a medium saucepan:

If using, remove the vanilla bean and set aside. Slowly pour half the hot milk over the egg mixture while whisking it constantly. Whisk the tempered egg mixture into the saucepan with the remaining milk and cook, stirring constantly, over medium-low heat until the cream thickens, about 2 minutes. Immediately scrape the custard into a clean bowl and stir in:

If you used a vanilla bean, scrape the seeds from the pod and stir into the pastry cream. If you did not use vanilla bean, stir in, if desired:

Place a piece of plastic wrap directly on the surface of the pastry cream to prevent a skin from forming. Let cool, then refrigerate before using. This keeps, refrigerated, for up to 2 days. When ready to use, transfer the pastry cream to a bowl, or a stand mixer with the paddle attachment, and beat on low speed until smooth and creamy.