Preheat oven to 355 degrees F (180 degrees C).
Beat Unsalted Butter (110 gram), Brown Sugar (45 gram), and Caster Sugar (35 gram) together in a bowl.
Mix in yolk of the Egg (1), followed by All-Purpose Flour (190 gram) and Salt (1 pinch). Fold in White Chocolate Chips (80 gram).
Press the dough into the inside of some glass-like molds so that there is an even layer on the bottom and up all sides. Chill for 30 minutes before baking.
Bake for 15 minutes.
Force a shot glass into the baked cookies as soon as they come out of the oven to reinforce a neat shot shape. Allow to cool.
Warm the Milk (11/2 tablespoon) in a microwave and pour it over the Dark Chocolate Chips (90 gram). Stir until the chocolate has melted completely.
Let it cool slightly before coating the insides of the cookie shot glass with chocolate and chill in the fridge till the chocolate hardens.
In a cup with Nestle® Milo (5 tablespoon) and Coffee Creamer (1 package), fill in Water (to taste) until it is only 1/3 full. Mix well until thoroughly dissolved before adding the Ice (to taste) to cool down the mixture.
Right before serving, pour the chilled milo into the shot glass and top with Nestle® Milo (2 tablespoon). You can add Redondo biscuits for garnish.