This recipe yields 6 cups or 1.5 liters

• Simmer the milk with the cinnamon stick, pinch of nutmeg, and lemon peel in a saucepan at medium heat for 10 minutes.  This will infuse the flavors from the spices into the milk and give it that wonderful spiced aroma.
• While the milk is simmering in a medium-size bowl, beat the egg yolks

  with the electric mixer until they are fluffy and turn into a pale-yellow color.
• Remove the milk from the stove and cool down for about 5 minutes before incorporating it into the eggs.
• Add a small amount (about a half cup) of the hot milk to the egg yolks and hand whisk. Then add another half cup and whisk again, repeating until the two are thoroughly mixed. This gradual addition keeps the eggs from coagulating when mixed with the hot milk.
• Return the mixture to the saucepan and cook at low heat, constantly whisking until it thickens (about 10 minutes). This cooking step at low heat is essential because a higher heat will boil the mixture and make the eggs curdle, resulting in a grainy texture.  Cooking at low heat also avoids clumping and sticking to the pot.The mixture will be done when it shows a light custard-like consistency and it fully coats the back of a spoon.
• Remove from the heat and let it cool down.  Discard the cinnamon stick and lemon peel.
• Add the cooled custard, vanilla, condensed milk, and rum to a blender.  Blend at medium speed for about one minute until mixed. This ensures a smooth and homogenous texture throughout without making it frothy.
• Taste (always taste!) and add more rum too if you wish.
• Transfer to a clean and sterilized bottle and let it cool down at room temperature, then refrigerate for at least 2-3 hours before serving. Note, I recommend letting it sit in the refrigerator overnight because the flavors intensify (It will be worth the wait).
• I love mine served with ice, but without it is also fantastic. Cheers! Salud!