Estonian Kringle (Estonia)

Dough

• 30 g sugar
• 1 lemon thin peelings of skin only
• 120 g milk
• 30 g unsalted butter diced
• 15 g fresh yeast crumbled
  ou 1 ½ tsp dried instant yeast crumbled
• 1 egg yolk from medium egg
• 300 g strong white bread flour plus extra for dusting
• 1 pinch fine sea salt

Filling

• 50 g halved walnuts
  ou mixed candied fruit
• 50 g unsalted butter soft
• 60 g sugar
• 2 Tbsp ground cinnamon

Icing

• 20 g egg whites lightly beaten
• 50 g icing sugar