For the orange-campari muffins, preheat the oven to 200°C degrees and line a muffin tin for 12 muffins with paper cups.
Mix the flour with the baking powder, cinnamon and baking soda. Beat the two eggs in a bowl and mix with sugar, oil and orange juice. Fold the flour mixture into the batter and pour the batter into the pan.
Bake the muffins at 200°C degrees for about 20 to 25 minutes. Let the finished muffins cool down and prepare the glaze: To do this, mix the powdered sugar with Campari until smooth and spread over the cooled orange Campari muffins.