1. 1. Prepare Your Dough Base: In a large mixing bowl, combine the sourdough discard, all-purpose flour, granulated sugar, baking powder, baking soda, and salt. Stir these dry ingredients together thoroughly until they are well combined.

2. 2. Add Wet Ingredients: Pour in the 1/2 cup of milk and 1/4 cup of melted butter into the dry mixture. Mix everything with a spoon or spatula until a shaggy dough forms. Be careful not to overmix; a few lumps are perfectly fine.

3. 3. Form the Dough: Turn the dough out onto a lightly floured surface. Gently knead it a few times, just enough to bring it together into a cohesive ball. Then, use a rolling pin to roll the dough into a rectangle, approximately 1/4 inch thick. Aim for a rectangle about 12×8 inches.

4. 4. Create the Cinnamon Filling: In a small bowl, combine the 1/2 cup packed light brown sugar and 1 tablespoon of ground cinnamon. Stir them together until the cinnamon is evenly distributed throughout the sugar.

5. 5. Assemble the Rolls: Evenly sprinkle the cinnamon-sugar mixture over the entire surface of the rolled-out dough rectangle, leaving a small border (about 1/2 inch) along one of the longer edges. Starting from the opposite long edge, tightly roll the dough into a log.

6. 6. Slice and Bake: Use a sharp knife or unflavored dental floss to cut the log into 1-inch thick slices. You should get about 12-15 mini rolls. Arrange the slices in a lightly greased 8×8 inch baking dish or on a parchment-lined baking sheet, leaving a little space between each roll.

7. 7. Bake to Golden Perfection: Preheat your oven to 375 F (190 C). Bake the mini cinnamon rolls for 15-20 minutes, or until they are golden brown on top and cooked through. The rolls should feel firm to the touch and smell wonderfully fragrant.

8. 8. Prepare the Glaze and Finish: While the rolls are baking, whisk together the powdered sugar, 1 teaspoon vanilla extract, and 2-3 tablespoons of milk in a small bowl until smooth and pourable. Once the rolls are out of the oven, let them cool for a few minutes, then drizzle generously with the prepared glaze. Serve warm.