Pillowy soft mushroom-shaped milk buns topped with cookie crust and filled with Oreo cookies and cream cheese filling are a must to try. Recipe is also available for sourdough version.
Place all ingredients, except for the butter and melted chocolate, in a mixing bowl of a stand mixer fitted with a dough hook attachment. Use the hook to stir everything around a bit so when you turn the machine on, the flour won't fly around and wet ingredients won't splash. Start with the lowest speed to mix things up and then increase to speed 2 and knead for about 5 minutes or until it forms a dough. If the dough is too dry to come together, you can add a bit of milk one teaspoon at a time. Don't add too much as we haven't added butter yet
Then add melted chocolate all at once and softened butter, in 3-4 batches. The dough will turn into a complete mess again because of the butter, but don't worry, it will get absorbed by the dough as it knead. Knead at speed 4 for about 10 minutes or until dough is smooth and elastic. If you slowly stretch a small amount of dough, it will not break and light can pass through, like a window pane. Proceed to first proofing
If using sourdough starter:
I use stiff levain because we are working with enriched dough that has butter and sugar added, which naturally slows down fermentation. Stiff levain is more powerful compared to regular liquid starter.
About 8-10 hours before you plan to make the bread, combine all ingredients for the stiff starter in a bowl. Stir a bit to roughly combine and then use your clean hand to knead it. This is a stiff starter, it's like a dough. Make sure no pockets of dry flour is visible. Transfer to a large see-through container (plastic or glass is fine, preferably wide-mouth so you can get it out easier later). Loosely cover with the lid and let it ferment until triple in size
Place all ingredients (except for butter and melted chocolate), including all of the stiff starter, in a mixing bowl of a stand mixer fitted with a dough hook attachment. Use the hook to stir everything around a bit so when you turn the machine on, the flour won't fly around and wet ingredients won't splash. Start with the lowest speed to mix things up and then increase to speed 2 and knead for about 5 minutes or until it forms a dough. If the dough too dry to come together, you can add a bit of milk one teaspoon at a time. Don't add too much as we haven't added butter yet
Then add melted chocolate all at once and softened butter, in 3-4 batches. The dough will turn into a complete mess again because of the butter, but don't worry, it will get absorbed by the dough as it knead. Knead at speed 4 for about 10 minutes or until dough is smooth and elastic. If you slowly stretch a small amount of dough, it will not break and light can pass through, like a window pane. Proceed to first proofing
First proofing:
Transfer to a lightly oiled bowl, cover, and proof at a warm place until double in size. If you use commercial yeast, this may take about 1-2 hours. When you poke the dough with your lightly-floured finger, the indentation stays and the dough has clearly almost doubled or doubled in size
If you use sourdough starter, proof for 2 hours 78-80 F (26-28 C). The dough may not double in size and just rise slightly, that's okay. It doesn't have to double in volume
Prepare the filling:
While waiting for first proofing, prepare the filling. Break Oreo cookies into pieces and add this to a food processor along with the cream cheese and process into a paste-like consistency. Divide into 12 portions
Prepare the crust:
Combine all ingredients for the crust. Transfer to a piping bag and set aside at room temperature. If it's really hot where you are, you can park it in the fridge and just let it soften at room temperature before piping
Shaping:
I use muffin pan to create a "mushroom" effect on the buns. Oil the pan to prevent sticking
Punch the dough down and give it a knead for a few times. Divide into 8 equal -size smaller dough. Round up each dough to roughly form a ball. Cover and let them rest for 10 minutes
Remove the fillings from 3 Oreo cookies and crush the cookies into fine crumbs. Add the cream filling to the filling you prepare earlier and combine
Then work with one dough at a time, flatten the dough with your palm and roll into about 4-inch circle. Put one portion of the filling on the center. Pull the edge of the dough towards the center and pinch the dough to seal it shut. Pick up the dough and dip the smooth surface onto Oreo cookie crumbs. Place this into one of the cavities in the muffin pan. Repeat with the rest of the dough and filling. Try to space out the dough so they aren't too close together because they will expand during baking (I didn't think of that!)
Final proofing:
Cover the shaped buns with a clean cloth or plastic cover and let them proof again at a warm place until they are puffy and almost double in size. If you use commercial yeast, this may take 45 minutes to 1 hour or longer depending on the temperature. If you use sourdough starter, this may take about 3 1/2- 4 hours or longer, depending on the temperature and the strength of your starter. Final proofing usually takes much longer for sourdough. The dough has a dome shape on top after proofing
When you gently push on the dough, the indentation bounces back very gradually and may leave a bit of indentation.
Baking:
10 minutes before the end of final proofing, preheat oven to 375 F (190 C). Place the baking sheet in the middle rack and bake for 20 minutes or until golden brown. Rotate the pan halfway through baking
Cool down:
Remove from the oven and let the buns cool inside the pan for 2-3 minutes and then carefully remove from the pan onto a cooling rack to let them cool down completely