Ingredients:
- 4 whole egg
 - 6 oz sugar
 - 4 oz cognac
 - 2½ oz espresso liqueur
 - 2½ oz fresh brewed espresso
 - 12 oz whole milk
 - 8 oz heavy whipping cream
 
Garnish: grated nutmeg
Glassware: Chilled coupe
Yield
one cocktail
Method
Pull a double shot of espresso and allow to cool. Crack the eggs into a blender and then begin blending on low, slowly adding all the other ingredients in the order listed. Pour into a serving container and let rest in the fridge for a whole day before serving. Garnish with nutmeg, cinnamon stick, or something seasonal.

Source: www.instagram.com
          
        This is the original template, but it begs for your personal touch: salted caramel liqueur, curaçao, or whatever floats your boat!