Dark Chocolate Muffins with a Surprise

INGREDIENTS 2 cups plain flour 2½ cups golden caster sugar ¾ cup unsweetened cocoa powder 1 tbs baking soda 1 tsp salt ¾ cup vegetable oil, neutral one that does not have strong taste or smell, like canola, sweet almond or Carotino oil 1 cup soured cream 1½ cups water 2 tbs white vinegar (I [...]This week recommended product: MAGIC CUP by Avent Philips - non-spill soft or hard spouts - compatible