With so many options out there when it comes to plant based milks, it can be hard to decide which one you should use when baking. Different vegan milks have different textures, taste and nutritional content and those are all going to play a part in how your recipe comes out in the end.
Almond Milk/Oat Milk/ Soy Milk
Almond, oat or soy milk will be your best bet as a one-size-fits-all ingredient. They have the closest texture to cow's milk and can be subbed out 1-for-1 in most recipes.
Rice Milk/Hemp Milk
Rice or hemp milk on the other hand are more diluted and have a more watery texture so they're not ideal as a replacement.
Coconut milk comes in 2 varieties: boxed and canned. Boxed coconut milk will have a similar texture to almond milk but with a more distinct flavor. Canned coconut milk on the other hand is made with actual coconut meat so it is packed full of (good) fat. It's super creamy and it will make your cakes super moist.
The one kind of plant based milk you never want to use unless your recipe specifically calls for it is flavored milks. What makes the milk taste like chocolate, vanilla, eggnog or you name it, are some extra ingredients and sugars. They're going to alter the chemistry in your recipe and could lead to your bake browning too fast, collapsing in the middle, sticking to the pan or a whole other host of problems.
In summary, I recommend using unflavored almond milk as your old reliable. That's the one I use in everything at the bakery! When someone has a nut allergy, I use oat milk instead. It works the same but it is nut free. For muffins and pound cakes, coconut milk from a can is my go-to as it makes them extra moist and soft.