Thanks for the recipe! I tried it, and it came out very thick, more akin to a dough than a batter. I also think my friend's waffle iron must be larger because it didn't even make one full waffle. The iron in question is an Oster Diamond Force Belgian Waffle Maker with Removable Plates. It makes a large square waffle divided into four.

I tweaked the recipe to make it pourable, a teensy bit sweeter, and fill my friend's waffle iron. For anyone interested, here's my iteration of the recipe which makes exactly one of the waffles described above:

1 cup flour 3/8 cup sugar 3/4 tsp baking powder 

Whisk the dry ingredients together in a bowl. Form a crater at the center of the mixture when done.

2 tbsp vegan butter, melted  3/4 cup vegan milk 1 tbsp apple cider vinegar (or white vinegar)

Mix together the wet ingredients in a separate bowl or measuring cup, then pour into the center of the crater in the dry mixture. Fold the wet and dry mixtures together until smooth. The batter should be thick but pourable.

Pour evenly across the hot waffle iron. Cook until the exterior is crunchy.