Wash 2 mandarins thoroughly with cold water and slice them thinly.

Sprinkle 20g sugar evenly over the mandarin slices and let them sit for 20 minutes.

Cream 120g softened butter using a whisk until smooth.

Add 100g sugar and 2g salt to the butter and mix until well combined.

Separate 2 eggs into yolks and whites. Add the yolks to the butter mixture and mix well.

Add the egg whites and whisk quickly until fully incorporated.

Sift 150g cake flour and 5g baking powder into the mixture and fold gently using a spatula.

Add 30ml milk and mix until the batter is smooth and creamy.

Fill muffin cups halfway with the batter and place mandarin segments in the center.

Top with more batter until the cups are 80% full and place sugared mandarin slices on top.