Whisk the eggs and sugar vigorously for about 30 seconds or so. Add the milk, vanilla extract, and oil and continue to whisk. The mixture will emulsify
Sift in all-purpose flour, tapioca starch, baking powder, salt, and custard powder into the wet ingredients. Use a whisk to mix until there is no lumps in the batter. Strain the batter if necessary
Rest the batter:
Cover the batter and let it rest in the fridge for at least 1 hour or up to 24 hours.
When ready to cook the waffles:
Remove the batter from the fridge 30 minutes before you plan to cook so the batter has time to come to room temperature. Transfer the batter to a measuring cup with a spout for easier pouring
Preheat the electric waffle maker:
I preheat the waffle maker for about 10 minutes. My electric waffle maker doesn't have the ability to adjust the temperature. I think most can't.
Bake the waffles:
Once the waffle maker has been preheated, brush with a bit of oil. You can use non-stick cooking spray too.
Give the batter a stir
Pour the batter into the mould, about 2/3 full. Do not overfill the waffle maker or they will overflow. If you fill too much, the waffles also won't turn out crispy.
You can use a rubber spatula to help you spread the batter to fill up the mold evenly.
Close the waffle maker and let it bake until they are golden brown or until the electric waffle maker says it's ready. They appear soft when you get them out from the waffle maker
Place the cooked waffles on a cooling rack in one layer. DO NOT stack them as condensation forms, making the waffles soggy.
The first few waffles may not be as perfect as you imagine because you probably still trying to figure out how much to fill out the mold and how long to bake them, but you will get the hang of it as you continue to work on it. Remember to give the batter a stir before you fill the waffle maker
If you want to form a cone :
As soon as you get the waffle out of the waffle maker, gently fold them in half to form a cone shape and put it in a cup to hold the shape as it cools down. You need to do this soon enough before the waffles crisp up and you won't be able to fold it anymore
How to serve:
This can be filled with some ice cream and toppings as you wish. See my post below for more suggestions.