Put the flour, salt, sugar and vanilla sugar in a mixing bowl and mix together. Add the soy milk and stir everything together, then add the mineral water and stir with a hand mixer until all the lumps are gone. Let the dough rest covered for 1 hour.
Brush a coated pan with a little oil and heat. As soon as the pan is really hot, thinly pour some batter into the pan and bake the pancakes. Keep warm until they`re all baked. Then place on a large flat plate and spread thinly with strawberry jam. Fold or roll up and serve immediately.