Sourdough Discard Cinnamon Rolls are my favorite way to use up extra sourdough discard, and they never disappoint!
Warm the milk in the microwave for about 1 1/2 minutes or heat it on the stove.
Add the melted butter and sourdough discard to the warm milk in a stand mixer bowl with a dough hook.
Mix lightly to combine. Sprinkle the instant yeast on top, allowing it to activate for about 10-20 seconds until you smell the yeast starting to bloom.
Add the granulated sugar, egg, and salt to the milk mixture. Gradually add most of the all-purpose and bread flours, reserving about 60g of flour to adjust the dough as needed.
Begin kneading the dough on low speed, adding the remaining flour as needed until the dough is tacky but not overly sticky. Knead for 8-10 minutes until the dough is smooth and elastic.