1. Cream together the softened butter, sugar, and brown sugar until light and fluffy (about 2-3 minutes).
2. Next add the sourdough discard, egg yolk, and vanilla until smooth.
3. To the same bowl add the flour, black cocoa powder, baking soda, and salt.
4. Mix until a soft dough is formed.
5. Refrigerate the dough for 1 hour or up to 24 hours before baking.

Shape & Bake the sourdough spider web Oreo's

1. Once the dough is ready, preheat the oven to 350 degrees F and line a baking sheet with parchment paper.
2. If the dough has been refrigerated for longer than 1 hour let it rest for 15-20 minutes to take the chill off.
3. I like to weigh each cookie to ensure they’re around 40 grams each (you should end up with 14-15 large cookies).
4. Pro tip: Gently roll each dough portion by hand to create perfectly round cookies.
5. Align about 6-8 cookies on your baking sheet (making sure they are spaced about 2 inches apart) and bake for 15 minutes.
6. Remove the cookies from the oven and firmly tap the tray on the counter to create those signature bakery-style cracks. This step is optional, but it adds a beautiful finish to the cookies.
7. Place the cookies back in the oven for 3-5 more minutes to ensure they are done baking. Every oven is different, so yours might only need the initial 15 minutes or it may need a few extra.
8. Upon removing them from the oven let them rest on the pan for 5 minutes before placing on a cooling rack. Let them cool completely before decorating.

How to decorate sourdough spider web Oreo's

1. Place about 1 cup of marshmallows in a microwave-safe bowl. Microwave in 10-second intervals, stirring between each, until the marshmallows are completely melted and smooth.
2. Let the melted marshmallow cool just enough that it's comfortable to handle but still stretchy.
3. Pinch a small amount of the marshmallow between your fingers and quickly stretch it back and forth over the completely cooled cookies to create thin, web-like strands.
4. Work quickly, as the marshmallow becomes more difficult to stretch as it cools. If needed, simply microwave it for another 5–10 seconds to soften it again.
5. While the marshmallow is still sticky, immediately add the candy eyes or Halloween sprinkles so they adhere to the cookies.

Storage

1. These Sourdough Spider Web Oreo Cookies are best enjoyed the day they're decorated, as the marshmallow webs are freshest and have the best texture.
2. Room Temperature: Store leftover cookies in an airtight container at room temperature for up to 2–3 days. The marshmallow webs may become sticky or lose their appearance over time.
3. Make Ahead: You can bake the cookies 1–2 days in advance and store them in an airtight container. Add the marshmallow spider webs and Halloween sprinkles the day you plan to serve them.

4. Freezing: The undecorated cookies can be frozen in a freezer-safe container for up to 3 months. Thaw at room temperature before decorating.

   My Tip: For the prettiest spider webs and best texture, I recommend decorating these cookies shortly before serving. The marshmallow webs look their best when freshly made!