Temperature of the oven (green) and the oil / Yorkshire puddings (yellow). I think I did not heat the oil quite hot enough this time (looks like about 410F), since the batter didn't sizzle as much as usual when I poured it in and I didn't get good cup shapes.

Batter is equal mass of eggs, soy milk, and all purpose flour (200g each / 4 eggs), whisked and rested overnight in the fridge.