Hot cross buns with a sourdough twist!
Feed your starter 8-12 hours before mixing together the dough.
Place all of the dough ingredients except for the butter into the bowl of a stand mixer fitted with a dough hook.
Knead on medium-low for 3 minutes. Slowly add the soft butter 1 tablespoon at a time, waiting until each tablespoon is fully incorporated before adding the next tablespoon.
Continue kneading for 15-20 more minutes, or until the dough passes the windowpane test.
Scrape the dough into a large greased glass bowl. Cover and allow to ferment at room temperature for 6-12 hours (depending on how warm your kitchen is), or until doubled.
Line a rimmed baking sheet with parchment paper.
Weight the dough and divide that weight by the number of buns you want to make. That works out to about 97 grams for 12 buns.
Take a piece of dough and pinch the corners into the middle for form a ball. Roll the ball, seam side down, on your work surface to create surface tension. Transfer the buns to the prepared baking sheet. The closer you place the buns, the taller they'll be.
Cover and allow the buns to rise for 4-8 hours, or until they're quite puffy.
30 minutes before the buns are done rising, preheat your oven to 375°F (190°C).
Whisk an egg with a bit of water. Brush the buns with the egg wash.
In a small bowl, whisk together the flour and water. Add enough water to make a paste that's thin enough to pipe, but not so thin that it will run off of the buns.
Pipe crosses on the buns, going straight down the middle of the buns.
Bake in the preheated oven for 23-25 minutes, or until the buns reach an internal temperature of 200°F (93°C)
Transfer the buns, parchment paper and all, to a wire cooling rack.
While the buns are still warm, brush them with either a simple syrup or warmed apricot jam.
In a small bowl, whisk together all of the icing ingredients. Again, you want a consistency that's able to be piped, but not so thin that it runs off of the buns.
Once the buns are completely cool, pipe the icing crosses in the same way as the flour paste crosses.
An active sourdough starter is one that has been fed 6-12 hours in advance, is bubbly and active, has doubled, and passes the float test.