Make the sweet starter: Mix ingredients for the sweet starter in a medium sized bowl. It’s a thick mixture so you may have to use your hands to get all the ingredients combined into a thick dough. If it is too dry after mixing by hand, add a sprinkle of water then knead together until there’s no dry flour left. Cover and leave at room temperature for 6 to 12 hours. It will double in size and become puffy and full of air.
Chop cranberries: Roughly chop up cranberries and set aside.
Prepare the orange: Zest one orange and set the zest aside. Juice the orange and set the juice aside to add later.
Warm milk: Add 175 grams milk (add extra since some will evaporate) to a small saucepan or pot. Warm until steaming and about 110 to 120º F.
Mix: Tare a bowl so that the weight shows zero. Add 165 grams of the warmed milk, the brown sugar, and the active sweet starter. Give it 3 to 5 stirs to begin breaking the starter apart. Add the flour, spices, and orange zest. Mix dough until all the liquid is absorbed. Add the salt, egg, and orange juice. Mix until dough is nearly smooth
Fold in butter and cranberries: Add the softened butter, fold in until dough is smooth. Continue kneading for 5 to 10 minutes (in a stand mixer on lowest two speeds, knead 3 to 6 minutes). Add the cranberries and fold the dough until they are dispersed throughout the dough. Once dough is smooth and pulls away from the bowl or work surface cleanly it has been mixed and kneaded enough.
Bulk fermentation: Cover the dough and allow to ferment 3 to 5 hours, until doubled in size.*
Stretch and fold: During bulk fermentation, stretch and fold the dough. Recover dough.
Divide dough: Divide dough into 12 pieces (about 77 to 78 grams each) to make medium-sized buns.
Prepare baking sheet: Cut a sheet of parchment paper and place it on a baking sheet (if you don’t have parchment, liberally grease the baking sheet or a rectangular casserole dish).
Shaping: Flatten a piece of divided dough with your hand, then gather edges into the middle. Turn over and roll dough against the work surface to tighten the dough into a smooth ball. Transfer shaped bun onto baking sheet. Repeat with remaining pieces dough. Arrange buns in baking dish to be spaced evenly apart, about 1 to 2 inches apart.
Proof: Cover shaped buns and proof in a warm place 1 ½ to 3 hours* until nearly doubled in size. Test proofing with a moistened finger gently pressed on surface. If finger leaves an indentation, go to the next step.
Preheat: Preheat oven to 400º F with a metal pan filled halfway with water on lowest rack.
Make crosses: Mix together flour and water for crosses. (If you are sensitive to gluten, but tolerate sourdough, skip this step and opt for iced crosses instead) Whisk flour and water well. Add to a piping bag or a plastic ziplock bag. Snip a tiny corner off the bag and pipe crosses on the buns from the bottom of one side across the top and down to the bottom of the other side.
Bake: Place rolls into oven and generously spray walls of oven. Close oven door and bake 20 to 24 minutes (start glaze—step 16), time will vary depending on size of buns and baking dish used. The rolls should expand and have a deep golden-brown color on top with the baked crosses standing out.
Make glaze: While buns are baking, melt the butter in a small pot or saucepan. Add the honey and water. Stir frequently until mixture is beginning to bubble.
Glaze: Right after buns come out of oven, generously glaze the buns all over until all the glaze has been used.
Cool: Cool until you can handle them safely and enjoy or allow to cool down until barely warm if you would like to add vanilla icing over the crosses.
Prepare vanilla icing: Sift powdered sugar and add remaining icing ingredients. Whisk until smooth and thick for piping. Place in a pastry bag with a thin round tip (substitute with a plastic ziplock bag with a very small corner snipped off) and pipe crossed on the tops of the buns with vertical and horizontal lines going through the middle of the buns.