Preheat an oven to 200 degrees C. Line muffin tin with 16 liners; set aside. Prick kumara several times with a fork and place onto a baking tray. Bake the kumara in the preheated oven until easily pierced with a fork, about 40 minutes. When cool enough to handle, peel and mash.
Reduce the oven temperature to 180 degrees C. Whisk together the flour, bicarb soda, salt and the spices. Stir in the vegetable oil, eggs, vanilla, honey, yoghurt and mashed kumara until all ingredients are just moistened. Spoon batter evenly into prepared muffin trays.
Blend together the oatmeal, brown sugar, almonds and the remaining cinnamon in a food processor or blender. Sprinkle topping over unbaked muffins.
Bake muffins in the preheated oven until golden and the tops spring back when lightly pressed, 12 to 15 minutes.