I make a sourdough oatmeal pumpkin bread this time of year. And happy coincidence, I just made it and have a small loaf and photos as shown below. Recipe was based on an “Artisan in 5 minutes per day” recipe from before my sourdough days. As you noted, it is an enriched dough and although I included my entire method, I think any method you normally use for an enriched dough is fine!!
240 grams pumpkin (I used pumpkin from sugar pumpkin that I cooked fresh and pureed)
334 grams water divided
1 T salt
4 T melted butter
100 grams honey (if you use canned pumpkin, you might want to increase honey or whatever sweetener you use … a little … I think ??)
55 grams rolled oats
100 grams whole wheat ( I used bolted Kamut this year instead of whole wheat)
90 grams rye flour
400 grams white flour
248 grams starter
I used a method that has been working well for me for high moisture doughs (***AND, this dough was pretty wet … I don’t think there would be any issue with adding a bit more white flour if you (or any baker making this) thought the dough was wetter than you/they wanted to deal with … baker’s call!)
For the starter build, in the morning or night before if you prefer: 100 grams active starter, 70 grams flour, 70 grams water. Mix well and leave at room temp until bubbly, active, floats. Now … you basically want 248 grams starter 100% hydration … how you get there is up to you, i.e. there is nothing magic about how much starter, how much flour and water to use to get to 248 grams.
About 2 hours before you want to use your starter (I know from experience, I am about 4 hours from mix to ready to use so about 2 hours in when I start in the morning … I do this step): mix all flours, oats and 284 grams water. Just a rough mix incorporating most of the flour. Let it set for 3-5 hours … your schedule … no magic time, you are just allowing the flour to absorb the water some.
Add levain and everything else. I whizzed all of the remaining water, pumpkin, salt butter and honey in a blender and added with levain to the flour mix.
I used a stand mixer to incorporate everything … after a bit, I let the mix sit for 30 minutes and then mixed again until the dough cleaned the bowl and whap, whap, whap against the side of the bowl.
Put dough - it is pretty wet and nearly pourable, into a clean bowl, cover and leave at room temp for 4-7 hours (I went 7 as my house is very cool at 63F and things happen slower, and especially with an enriched dough)
Refrigerate for 12 plus hours. The loaf below is 12 hours. I have a 2nd larger loaf that I’ll bake this afternoon, probably.
Shape, proof, bake.
I did this little loaf in a cast iron loaf pan, using a USA loaf pan as a lid: 500 preheated oven and pans for 25 minutes, lid off, temp to 450, 15 more minutes to temp of 203F. The 2nd loaf is larger and I intend to bake it in a clay oblong baker, but no reason this dough can’t be a boule baked in a dutch oven or round baker or whatever.
Flavor is slightly sweet. Crumb is softish like a sandwich bread. Crust is thin and crisp.