What to Do With Leftover Egg Yolks?

With all the mousseline buttercream that I had been making, I kept ending up with extra egg yolks. What to do with them that would be yummy?

Pastry cream.

I have a really great recipe that virtually guarantees no lumps (thanks Baking Illustrated!) The trick lies in tempering the egg yolk mixture with the hot milk before adding the whole thing back into the saucepan to continue cooking. Because of this technique, I didn't even have to strain my pastry cream and it came out perfectly smooth.

Pastry Cream (Makes about 3 cups)

Ingredients:

• 2 cups half-and-half
• 1/2 cup sugar
• Pinch salt
• 5 large egg yolks
• 3 tablespoons cornstarch
• 4 tbsp. cold unsalted butter, cut into 4 pieces
• 1 1/2 tsp. vanilla extract

Directions:

1. Heat half-and-half, 6 tablespoons of the sugar and the salt in a saucepan over medium heat until simmering, stirring occasionally to dissolve the sugar.
2. Meanwhile, whisk egg yolks and remaining 2 tablespoons of sugar in a medium bowl until sugar begins to dissolve. Whisk in the cornstarch until combined and the mixture is pale yellow and thick.
3. When the half-and-half mixture reaches a full simmer, gradually whisk half of that mixture into the yolk mixture to temper it. Stir to ensure even mixing. Return the mixture back to the saucepan; whisking constantly until a few bubbles burst on the surface and the mixture is thickened.
4. Remove from heat and whisk in the butter and vanilla. (If needed, strain through a fine-mesh sieve).
5. Let cool thoroughly, at least 3 hours.

Then what? So I ended up making cream puffs to go with the pastry cream. Here they are puffing in the oven: