This is the opposite to sourdough (
) but I've had good results just switching in 100% rye to a variety of sweet breads and cakes.
We briefly had a reliable rye loaf, but then our flour source disappeared and the new flour was coarser. Think it was good last time we made it, but it was part of a giant holiday gift baking session so then there was tonnes of stuff to eat and the rye didn't really get eaten.