German New Year Pretzel - cooking recipe

Ingredients

6 1/4 teaspoons active dry yeast
1 cup lukewarm milk, divided
4 1/2 tablespoons white sugar
2 1/4 cups all-purpose flour, sifted, or more as needed
4 1/2 tablespoons melted butter
1 egg
1 teaspoon lemon zest
1 pinch salt
1 egg yolk
1 teaspoon white sugar, or as needed

Preparation

Dissolve yeast in 1/2 cup milk in a bowl; add 4 1/2 tablespoons sugar. Let stand until the yeast softens and begins to form a creamy foam, about 5 minutes.
Stir yeast mixture and 2 1/4 cups flour together in a bowl until dough is dry and clumpy. Allow dough to rise for 15 minutes. Add remaining 1/2 cup milk, butter, egg, lemon zest, and salt to dough until evenly mixed.
Knead dough, adding more flour as needed, until dough is elastic. Cover bowl with a clean damp towel or plastic wrap and allow dough to rise in a warm area until doubled in size, about 1 hour.
Preheat oven to 390 degrees F (199 degrees C). Grease a baking sheet.
Gently knead dough; roll into a long rope on the prepared baking sheet and twist into a pretzel shape. Cover dough with a clean towel or plastic wrap and allow to rise for 15 minutes more.
Brush egg yolk over dough and sprinkle 1 teaspoon sugar over egg yolk.
Bake in the preheated oven until golden brown, 25 to 30 minutes.