
In a large heavy-bottomed saucepan, add the milk, vanilla, cinnamon stick and cloves. Heat over medium-high heat while stirring constantly with a wooden spoon or spatula. This is to prevent the milk to sticking to the bottom of the pot.
Once the milk is about to start boiling, add the baking soda, cornstarch, and condensed milk or sugar. Keep stirring all ingredients are integrated well. About 3 minutes.
Turn the heat down to medium-low and continue to cook and stir often for about 15 minutes. At this point the milk will reduce about ⅓ and that's okay.
Remove from heat and set to cool for 40 minutes before we add the yolks.
Important Note: Keep stirring or whisking often to prevent the milk to sticking to the bottom of the pot.
Reserve one cup of the liquid/milk and set aside to cool.
In a large bowl or cup, whip the egg yolks until fluffy and it does not stick to the whisk. Once the 1 cup milk has cooled, slowly add it to the eggs while whisking at the same time. Make sure the milk is not hot otherwise the eggs will cook and not integrate well into the milk.
Continue whisking until fluffy.
Now add the egg/milk mixture into the rest of the milk and continue to whisk to integrate all ingredients.
Return pot to the stove and heat over medium high eat. Whisking constantly. When it starts to boil, reduce heat to low and cook for about 5 minutes.
Remove pot from heat, remove the cinnamon and cloves and cool for about 10 minutes.
Add the ½ cup of rum, brandy or whatever alcohol you prefer to use and transfer to a pitcher or jars.
Serve hot or cold and garnish if desired.