Blend yoghurt, banana, maple syrup and oil or melted butter with a blender. Whisk in the egg. Also using a blender, blend the oats so you get oat flour. Mix oat flour with spelt flour, salt, cinnamon, baking powder and optionally cardamom and almond flour. Peel carrots and the apple and grate finely.
Add the flour-mixture to the yoghurt-egg-mixture and fold in carefully. Add grated carrots and apple as well as the chopped almonds. Place the batter in 12 muffins tins. If you like you can add some chopped walnuts on top.
Bake the muffins in the preheated oven at 175°C (347 °F) for about 20 minutes.