1. Preheat your oven to 375 F (190 C). Line a large baking sheet with parchment paper. Lightly flour a clean work surface.

2. Carefully unroll the crescent roll dough onto your floured surface. Do not separate the individual triangles. Gently press along the perforations to seal them together, creating one large rectangle.

3. In a small bowl, combine the melted butter, sourdough discard, granulated sugar, ground cinnamon, and optional vanilla extract. Whisk thoroughly until all ingredients are well combined and form a thick, spreadable paste.

4. Evenly spread the cinnamon-sourdough mixture over the entire surface of the crescent dough rectangle, going almost to the edges.

5. Using a pizza cutter or a sharp knife, cut the dough lengthwise into approximately 1-inch wide strips. Take each strip and gently twist it several times, creating a spiral shape.

6. Place the twisted strips onto your prepared baking sheet, leaving a little space between each one. Bake for 12-15 minutes, or until the twists are golden brown and puffed up. Keep an eye on them to prevent over-browning.

7. Carefully remove the baking sheet from the oven. Let the cinnamon twists cool on the baking sheet for a few minutes before transferring them to a wire rack. Dust with powdered sugar, if desired, before serving warm.