Preheat oven to 180C/350F and grease a 12 hole muffin tin.Place the flour, oats, baking powder, bicarb, spices and sugar into a large bowl and stir until combined.Add in the grated carrot and apple and stir until they are coated in flour.Place eggs, vanilla extract, milk and vegetable oil into a jug and beat lightly.Pour over the dry ingredients and mix until there are no lumps of flour left. Don't beat or be tempted to keep mixing, otherwise you may end up with rubbery muffins.Divide the mixture between the greased muffin holes, fill each one level.Place in the oven for 15-20 minutes, until risen, lightly golden and an inserted skewer into the centre comes out clean.Leave to cool in the tin for 10 minutes, before transferring to a wire rack to cool completely.Once cooled, muffins will keep in an airtight container, at room temperature, for 5 days.