In the bowl of a stand up mixer whisk together the flour, salt, zest and sugar, make a well in the centre and add the milk and yeast, mix together with a fork. Then add the egg. With the dough hook attachment knead for approximately 1 minute just to combine.
Cover the bowl with plastic and let rise 2 hours, every 30 minutes fold both ends into the middle (repeating 4 times).
When the time has passed add the butter a little at a time, on medium high speed with the dough hook, knead just to combine all the butter, then let the dough rest 10 minutes. Knead again for 5-6 minutes until smooth and the dough does not stick to the sides of the bowl. Place the dough in a lightly greased bowl, cover with plastic and refrigerate for 1-2 hours.
Move the dough to a lightly floured flat surface. Divide the dough into 4 parts. Roll each part into 2 ropes (10-12 inches / 25-30cm), join 2 ropes at the top and twist the ends one over the other (see photo), join the ends to form a wreath (circle) repeat with the remaining ropes. Place the wreaths on a parchment paper lined cookie sheet, cover and let rise in a warm draft free area for 1-2 hours or doubled in bulk.
15 minutes before rising time has finished pre heat oven to 390F (195C).
Add a dyed uncooked egg (if desired) to the centre of the wreath then brush the wreaths with the egg wash (be careful not to brush the eggs) and sprinkle with the sprinkles. Bake for approximately 20 minutes or until golden, or when tapped on the bottom and there is a hollow sound. Immediately move the baked buns to a wire rack to cool. Let cool before serving. Enjoy!
In a small bowl beat together the egg and water.
If the area where the dough rises is cooler, then be sure to let the dough rise longer.*I used nonpareils and not jimmies, these are the tiny round rainbow coloured balls used for decorating.