6-12 hours (at least 6-8 hours in warmer months, 10-12 in cooler months) before you make your dough, mix together 100 grams of all-purpose flour (2/3 cup) and 50g water (3 T. and 1 t.) with 40 grams of sourdough starter (about 2 T.) in a small bowl. Cover with plastic wrap and let this sit at room temperature to become active for 6-12 hours. Once it is more than doubled in volume, puffy, and has an aerated appearance, it is ready to use.
Measure out more milk than the recipe calls for (about 180 grams or 2/3 cup) into a small pot and heat over medium heat until steam is rising off the milk and you can begin seeing the proteins on the bottom of the pot. Remove from heat and pour the milk into a glass measuring carafe to cool to no more than 100 degrees F before adding it to the dough when needed.
Place a large mixing bowl or a stand mixer bowl on a kitchen scale. Add 150 grams of the scalded milk, pumpkin puree and brown sugar. Followed by the active stiff starter. Use a spoon to break the starter apart before adding the dry ingredients (bread flour, whole wheat flour, salt, and spices). Give the ingredients 3 to 5 stirs then add the egg.
Mix the ingredients together using a spoon or a dough hook attachment, if using a stand mixer. Be sure to check under the dough and the sides of the dough for dry flour as you mix.
Once the dough is no longer sticking to the sides of the bowl and is becoming strong and elastic, add the softened butter. Knead the butter into the dough until it is completely incorporated and the dough is smoother and can be formed into a dough ball. Place your dough into a dough bin or a clean bowl and cover with plastic wrap.
This enriched dough will take 3 to 6 hours at room temperature.
Line two baking sheets or baking trays with parchment paper.
Place dough on a lightly floured surface. Divide the dough into 12 equal pieces. Divide by weight (about 83 grams each) or by quartering dough and dividing each quarter into three pieces to create 12 total.
Flour the work surface. Take a piece of dough and roll under hands into a rope shape. The rope should be about 16 inches long. Make a loop on one third of the rope leaving a short 2 to 3 inch section and a long 5 to 6 inch section. Take the long section of rope and wrap it around the loop 2 to 3 times until length is gone, then tuck end under the roll. Take the short section of the rope from the other side and wrap it around the loop once to bring the ends together under the roll. Press ends under roll to seal shape. Place pumpkin shape onto parchment lined baking sheet.
Repeat with the rest of the pieces of dough.
Rolls should be spaced with at least 3 inches between them, use another parchment lined baking sheet if you run out of room. Cover the rolls with plastic wrap.
Let the shaped dough rise at room temperature for 2 to 4 hours until the rolls are nearly doubled in volume. Test the proof by poking one of the rolls. If the indentation remains, it is time to preheat the oven.
Preheat the oven to 375 degrees F.
Whisk egg wash ingredients together. Use a pastry brush to brush the egg wash over the tops of the rolls. Brush the entire surface of the pumpkin rolls and in the crevices.
Place rolls into oven and use spray bottle to quickly spray walls of oven with water for an extra blast of steam. Close oven and bake 18 to 20 minutes. Color will darken slightly and inner temperature should be at least 180 degrees F.
While the rolls are baking, take pecans and cut in half, lengthwise. These will become the decorative “stems” for the pumpkin rolls. Place pecan halves upright in the center of the rolls after baking.
Transfer the sourdough pumpkin rolls to a wire rack to cool. Rolls are ready to enjoy once they are cool enough to handle or after 30 minutes of cooling.