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.

Melt the butter and set aside. To a separate bowl whisk together the brown sugar and cinnamon.

Lightly flour a sheet of parchment paper and place your dough on top. Sprinkle a little flour on your rolling pin to prevent sticking, then roll the dough out into a 10x13-inch rectangle.

Pour the melted butter over the surface of the dough and use a pastry brush or the back of a spoon to spread it evenly to the edges. Sprinkle the cinnamon-sugar mixture over the top in an even layer.

Using a pizza cutter, slice the dough in half lengthwise, then make vertical cuts every 1.5 inches to create about 16 sticks total.

Gently slide the parchment paper and cinnamon sticks directly onto a baking sheet.

Bake in a preheated 350°F (175°C) oven for 18–22 minutes, or until the centers are fully baked. The internal temperature should read at least 190°F (88°C) for doneness.

Using an electric hand mixer, beat the cream cheese and butter together on medium speed in a medium mixing bowl . Mix until they are well combined and have a smooth, creamy texture. This should take about 2-3 minutes.

Reduce the speed of your hand mixer to low. Slowly add the powdered sugar, about one cup at a time. This prevents a sugary mess and ensures that the powdered sugar is incorporated evenly into the mixture.

After each addition of powdered sugar, increase the mixer speed to medium and continue to blend until the frosting becomes smooth and well combined. Be sure to scrape down the sides of the bowl with a spatula to ensure even mixing (optional: adjust the consistency by adding a teaspoon of milk at a time).

Drizzle the frosting over top or use it as a dipping sauce!

These cinnamon sticks stay fresh for up to 3 days at room temperature in an airtight container, or can be frozen for up to 2 months.