• The sourdough discard brioche dough can be mixed by hand or a stand mixer.
• Warm the milk in the microwave for 30–45 seconds, then add it to a mixing bowl with the sour cream (or Greek yogurt) and stir until the mixture is smooth and well combined.
• Stir in the sourdough discard and sugar until mostly dissolved. Then whisk in the egg and vanilla extract.
• To a separate bowl whisk together the flour, baking soda, baking powder, & salt, and slowly add it to the wet mixture along with the softened butter.
• Mix until the ingredients come together into a shaggy dough, then cover and let it rest for 20–30 minutes to hydrate and relax.
• After resting, knead the dough until it becomes fairly smooth, being careful not to add too much extra flour, as this can alter the final texture. It should remain slightly sticky even after kneading.
• Once complete, cover the dough and let it rest for another 15-30 minutes.

Make the apple filling & crumble topping

• For the apple filling: Melt the butter in a skillet over low-medium heat. Add the diced apples, brown sugar, cinnamon, nutmeg, and salt. Cook 4-5 minutes until softened, but not mushy.
• Stir in the lemon juice (if using) and corn starch slurry and cook briefly until the mixture has thickened. Cool completely before using.

  *The filling can be prepared the night before and refrigerated before using for flexibility.
• For the crumble topping:  In a small bowl, combine cooled melted butter, both sugars, cinnamon, salt, and flour. Mix until crumbly and chill until ready to use. If the mixture is too wet add a little more flour. If it is too dry. add a little more melted butter.

  *The crumble can be prepared the night before and refrigerated before using for flexibility.

Shaping sourdough discard apple cinnamon roll muffins

• Line a 12 cup muffin pan with muffin liners and preheat the oven to 350 degrees F.
• Mix the cinnamon sugar base layer: mix together the softened butter, brown sugar, and cinnamon until a paste is formed.
• After resting, roll the dough out on a lightly floured surface into a 20×10-inch rectangle. Tip: flour your rolling pin to avoid it from sticking.
• Spread the cinnamon sugar base layer on the surface of the dough leaving a 1/2-inch border. Then scatter the apple filling across evenly and press gently to adhere.
• Using a ruler or visually estimating, lightly score the top of the dough every 1.5 inches to help guide the cuts and maintain uniformity. Use a pizza cutter to make clean, straight cuts through the dough. You will end up with 12 muffins total.
• Roll each apple cinnamon roll individually as tight as possible to keep all the filling in and place each one into the muffin pan. These rolls are a bit thicker and may need to be gently pressed into each muffin cup to fit.
• Sprinkle the crumble topping generously over each roll and bake for 28-32 minutes or until the internal temperature reads 190-200 degrees F.
• Allow the sourdough discard apple cinnamon roll muffins to rest for 10-15 minutes before removing from the pan. While they rest make the optional caramel glaze.

Make the caramel glaze

• In a small saucepan, melt the butter and brown sugar together. Stir in the heavy cream and simmer 1-2 minutes until smooth. Remove from heat and stir in the pinch of salt. Let cool sightly to thicken.
• If the glaze thickens too much add a splash of milk to thin it out.
• Generously glaze each cooled apple cinnamon roll muffin and enjoy!
• Sourdough discard Apple cinnamon roll muffins last for 2-3 days on the counter in an airtight container or 5 days in the refrigerator.