Preheat the oven to 400 degrees. Grease 12 cup muffin pan or use paper liners. Sift together the flour, baking powder, baking soda, and salt into a large bowl. Stir in the sugar & walnuts.
Lightly beat the eggs in a large bowl then beat in the yogert, oil, orange rind, and chopped rosemary leaves. Make a well in the center of the dry ingredients and pour in the beaten liquid ingredients. Stir gently until just combined. Do not overmix.
Spoon the batter into the prepared muffin pan. Bake in the preheated oven for about 20 minutes, until well risen and golden brown.
Let muffins cool in the pan for 5 minutes and serve with warm.