In a large mixing bowl, combine the all-purpose flour, bread flour, sugar, salt, instant yeast, cinnamon, and nutmeg. Mix well to combine.

In a separate bowl, whisk together the warm milk, melted butter, and egg until smooth.

Pour the wet ingredients into the dry ingredients and mix until a dough forms.

Add the raisins (and candied orange peel if using) and knead the dough on a floured surface for about 8-10 minutes until smooth and elastic.

Place the dough in a greased bowl, cover with a damp cloth, and let it rise in a warm place for about 1 hour or until doubled in size.

Once risen, punch down the dough and divide it into 12 equal pieces. Shape each piece into a ball and place them in a greased 9x13-inch baking dish, leaving a little space between each bun.

Cover the dish with a cloth and let the buns rise again for about 30-45 minutes, or until they have puffed up.

Preheat the oven to 375°F.

Bake the buns for 20-25 minutes or until golden brown.

While the buns are baking, prepare the glaze by mixing the powdered sugar, water, and vanilla extract in a small bowl until smooth.

Once the buns are done, remove them from the oven and let them cool slightly before drizzling the glaze over the top.