Make up to 3 days ahead and refrigerate. Have the sauce at room temperature before using.
- 2-1/2 cups whole milk
- 4 tablespoons unsalted butter
- 4 tablespoons flour
- Salt and freshly ground pepper
- 1/4 teaspoon ground cinnamon, or to taste
- 1/4 teaspoon freshly grated nutmeg, or to taste
- 4 large eggs
1. Make the Béchamel: Heat the milk in a small saucepan over medium heat to hot, but not bubbling. In a 3-quart pot over medium heat, melt 4 tablespoons of butter. When the butter is foaming, stir in the flour with a flat bottomed wood spatula and cook for 2 minutes, taking care not to let the roux brown. Add the hot milk and whisk quickly to combine, making sure there are no lumps.
2. Stir in salt and pepper to taste, and the cinnamon. Bring the sauce to a simmer and cook, stirring constantly, about 10 minutes, or until it is thick with no raw taste of flour. Add the nutmeg. You want to slightly over-season the sauce as the eggs and baking mute flavors. Set aside to cool.
3. In a large mixing bowl, beat the eggs together until frothy. Add the béchamel in batches, mixing in each addition until entirely smooth.