Combine the flour, oats, baking powder, salt and smoothie powder in a bowl. Make a well in the centre. Lightly whisk the egg, oil and milk and pour into the dry ingredients. Mix well. The dough should be soft but not too sticky. Pat a 1cm thick disc of dough onto a slightly-greased pizza or baking tray. Bake for 10 mins or until slightly golden.
Remove from the oven and spread with pizza sauce, top with vegetables and drizzle a little olive oil. Sprinkle with chilli flakes and season with salt and pepper.
Bake for a further 10 minutes. Service with dollops of yoghurt on each slice.