Since it sounds like they are basically a dried out batter at this point, I would turn to implementations that rely on those kind of food-stuffs;
- With some further baking and possibly additional brown sugar and butter or apple-sauce, I would use them for a crumble topping. If they are coffee and cinnamon an apple-cardamom cobbler would benefit nicely.
- The crumbles could be incorporated into a biscuit batter recipe
- In all likelihood, any kind of recipe that relies on a granola could probably be referenced for further ideas.
- You could also use the crumble as a stand-in for oat based no-bakes. The no-bakes might feel mealy to the tooth, so not entirely eliminating the oat might work best.
If you wanted to repurpose, you might try thinking of it as a material to be suspended. With an ingredient like well-blended coconut butter (not to be confused with coconut oil or milk or cream) you could create a base with which to make a kind of post-raw bar cookie (basically press and chill the coconut butter in a pan on top of wax/parchment paper, pulse the muffin bits with some dates or brown rice syrup, and once the butter sets press the bits/dates mixture into the top and drizzle with some ganache or whatever).
Unstrained yogurt has the exact same ratio of water/protein/fat as the milk that it was made from. The amount of sugar will be different as some of the sugar was converted to acid during the fermentation.
This means that yogurt can be substituted 1 to 1 for milk, and sometimes other liquids, in baking. Know that the pH of the batter will be lower and if that will be a problem then add a little more baking soda to compensate for it. The lost sugar won't usually adversely affect a recipe because they usually have plenty of sugar added.
Quickbreads don't usually have a lot of added liquid and adding a significant amount of yogurt would throw off the batter. It could still be good but it wouldn't be the same thing.
To mitigate that problem your recipe uses Greek yogurt. Greek yogurt has been strained which simply means that the yogurt was stirred to break up the protein mesh and some of the whey was allowed to drain off. The whey will be mostly water but will also contain some sugar, lactic acid, and riboflavin. Even with the whey drained off Greek yogurt is still mostly water. This water, however, is locked up in the protein mesh. Where normal yogurt will weep whey when cut, Greek yogurt will not (at least not so easily).
The yogurt will regardless add some liquid, a fair bit of protein and potentially fat, and some acid. The acid and fat will add some wonderful flavor while the protein and fat will interfere with gluten development. In quickbreads you don't need gluten so this is a good thing.
To compensate for the additional acid your recipe includes a little extra soda along with its baking powder.
In summary:
Yes you can add strained yogurt to a quickbread for flavor. Be careful not to add so much that the added water will throw things off and remember to add the extra soda to compensate.
Best Answer
Some muffins with very thick batter can be held for up to several days before being baked, but these are the exception, rather than the rule.
However, quick breads, whether sliced loaves, whole loaves, or muffins, freeze extremely well. Muffins are especially easy to reheat in the microwave or a toaster oven, and can be an ideal way to have quick breads prepared in advance.
Another way (which offers fresh, hotly baked breads) that I like I do before busy holidays that will have muffins or cornbread on the menu, is to prepare the dry mix, and the wet mix, and stick them (separately) into the refrigerator. Then, it is only a matter of combining them, putting them in the pan, and baking.