I have a question about the recipe "Nigella Lawson's Very Smart Strawberry Streusel Cake" from Sarah Jampel. Can I convert this to a muffin recipe? Do you have any tips for how? What should I adjust?
I think it would probably work. If you wanted to have that strip of strawberry jam, you'd have to pat the dough on for each individual muffin. You could probably lightly mix the jam in the dough to have more of a marbled effect if you don't want construct the dough/jam/dough layer for every muffin.
My main reservation would be sticking, both with mixing the jam into the dough and patting the dough up the sides as the recipe instructs. Since it says to grease a springform pan, be sure your muffin tin is well-greased too. I'm not sure how paper liners would work here, or if oiled liners would be good.
Be sure to decrease the baking time, maybe try something like 15-25min.
I guess it depends on how much you feel like experimenting.
Another option, adapting the original for use in muffin tins:
Use the dough and the strawberry slurry to make a kind of marble swirl cake, this time the strawberry (not chocolate) is the color note against a white background.
Agree with Stephanie B on needing muffin cups, either oiled paper or silicone.
And yes bake for a shorter time than the whole cake.
Look up some other streusel muffin recipes and use the instructions as a starting point. You can learn a lot by comparing similar recipes - I do this when I am not sure about adapting something.