Mix the yeast, warm water and vegan sugar together until frothy and then leave for 10 minutes. Sift the cake flour, bread flour and salt into this, mixing while you're sifting. As you start mixing, add the olive oil.
Knead the dough softly until it feels like playdough (you may need to add more flour to stop sticking). Leave to rise in a warm place (can wrap in clingwrap and place in the warmer if you don't have a lot of time). Once risen, knead down again (not too much), then roll out into your bases.