Measure out milk in a large liquid measuring cup. Then add vanilla and melted butter and whisk.
Add wet to dry and gently, slowly whisk until just combined. Small lumps are fine - don't overmix.
Let set for 5 minutes while you preheat your griddle to medium-low heat. You want it warm but not screaming hot - definitely on the low-side of medium.
Once hot scoop scant 1/4 cup measurements onto a griddle or pan lightly greased with non-stick spray. Should make ~10 pancakes (as original recipe is written). Flip when bubbles appear on top - 2-3 minutes. Cook for another 2 more minutes on the other side.
Place on a large plate and keep warm in a 200-degree F (93 C) oven until ready for serving.
Top with vegan butter, cinnamon sugar, and a drizzle of warm maple syrup or honey. I went with honey because it's what I had on hand + it made it feel like a true sopapilla experience. However, to keep these vegan, serve with agave or maple syrup.
Store leftovers in an airtight container or bag in the fridge to keep fresh, or the freezer for longterm storage. However, these are best when fresh.
*Nutrition information is a rough estimate. *This recipe is vegan besides the honey, which I highly recommend using to get the true sopapilla effect. However, if vegan simply sub agave or maple syrup instead.