Try to find a good traditional recipe. I use one that I agreed to not share. The only way "Granny Nillson" would share it with me. I use a Griswold 962, the gold standard. And I always make twice as much as I think I will need. Never any left over. The tablespoon or oil is very important, and "slipping" the partially cooked pastries requires a lot of attention. I usually put a dollop of jam, an apple wedge or a cube of cheese(savory style) inside. and do the final turn to close but cook until golden. Keep heat up to eliminate oiliness. I like a little syrup on top, or powdered sugar, or All fruit. If you make your own apple sauce, that would be great.
I didn't look at the referred video, but it helps to see them made. Think a little thin in the batter so you can get it to flow over the cooked edge.