Start by combining milk, granulated sugar, and instant yeast in the bowl of a stand mixer. Let it sit for a few minutes until the yeast becomes foamy.
In a separate medium-sized bowl, whisk together all-purpose flour, kosher salt, ground cinnamon, ground nutmeg, ground allspice, and raisins.
Add the eggs and melted butter to the yeast mixture and stir to combine.
Attach the dough hook to your stand mixer and mix on low speed until combined, about 1 minute.
Gradually add the flour mixture to the wet ingredients in two installments while continuing to mix on low speed for 4-5 minutes.
Cover the bowl with a towel and let the dough rise in a warm place until it doubles in size, which typically takes 45-60 minutes.
Once the dough has risen, punch it down gently to release the air. Transfer the dough to a floured surface and shape it into a ball.
Divide the dough into 4 equal parts, then divide each part into 3 equal pieces to get 12 pieces.
Roll each piece into a ball and place them in a greased 9x13-inch baking pan. Cover with a kitchen towel and let rise again in a warm spot for about 45 minutes.
In a small dish, whisk together the large egg and a couple of teaspoons of water. Brush this over the risen buns.
To make the paste for the cross, mix all-purpose flour and water until smooth. Transfer this mixture to a sealable bag and snip the corner.
Once the buns have risen, pipe the cross on each bun and bake for 20 minutes until golden brown.
After baking, allow the buns to rest for a few minutes. For the icing, whisk together the powdered sugar, milk, and orange zest. Brush this sweet mixture over the warm buns.
