Make the starter: 8 to14 hours before mixing your dough, mix ingredients for starter in a bowl. Cover and leave at room temperature to become active. It will double in volume and become full of bubbles.

Warm milk: Measure out at least 200 grams of milk into a saucepan (some will evaporate while it is heated so add a little extra to account for evaporation). Heat milk over medium heat until you begin to see steam rising off it or reaches a temperature of 115 to 120 degrees F. Let it cool down to 80-100 degrees F.

Scale: Once cooled, add 180 grams of the warm milk to the mixing bowl. Add the sugar, salt, and 200 grams starter. Allow the sugar and salt to dissolve. (Remember to use the scale’s tare function to remove the weight of the bowl and previous ingredients to only weigh the current item added) Add the flour.

Mix: Stir ingredients to begin to combine the flour with the liquid, then add the egg yolk. Continue mixing dough using the spoon and a dough scraper to scrape the sides of the bowl. (Mixing and kneading steps can be done in a stand mixer with a dough hook if available.)

Add butter: Add the butter once the dough is beginning to become smooth and continue mixing and kneading the dough.

Knead: Knead dough 10-15 minutes (4-7 minutes on lowest two speeds in a stand mixer) or until dough is smooth, no longer sticky, and releases easily from the bowl or work surface.

Prepare baking dish: Get out a large baking sheet and a large piece parchment paper. Place parchment paper on top of baking sheet.

Divide dough: Divide dough into 23 equal pieces (about 34g each). Weigh each piece to make sure they are roughly the same weight.

Shaping: Take a piece of dough and flatten it into a disc then gather the edges into the center and pinch to seal. Pull the edges of the ball into that same seam to tighten further. Turn the dough over onto the seam and rotate briskly under a cupped palm to tighten into a smooth ball. Repeat with the remaining pieces of dough. Note: you can arrange the balls of dough one- by-one as you shape or shape them all first then arrange.

Arrange the tree: The tree will consist of seven rows; 1 roll on row 1, 2 rolls on row 2,3 rolls on row 3, 4 rolls on row 4, 5 rolls on row 5, 6 rolls on row 6, and finishing with 2 rolls centered at the bottom for row 7 to create the trunk of the tree.

Proof: Cover and proof in a warm place 2 to 5 hours until rolls are puffy and about 1.5-2 times larger. A gentle finger poke should leave an indentation.

Preheat: Preheat oven to 375 degrees F.

Bake: Bake 20 to 25 minutes until rolls are golden brown.