Best Potatoes for potatoe bread

and caramelized in the oven.

I have even mashed leftover fried onion and potatoes into a dough which made a flavorful bread with dark bits of onion.   Baked and boiled potatoes will give you somewhat different texture and flavor results.  You may need to adjust your liquids to accommodate the potatoes' water content.    As far as the best potato variety, I have no preference.  Percentage wise, the amount of potato is small, so it would take more sensitive taste buds than mine to detect a difference.  I have used russets, red (waxy) and yukon gold potatoes in bread and rolls.

Although it really doesn't matter, I choose a high-starch potato, like Russets. (Gold-fleshed potatoes generally are low starch.) The starch is the point in using the potatoes in bread in the first place, to add moistness and softness. Method of cooking also doesn't matter, but usually I boil them, and then use the potato boiling water in the bread! Microwaving will work just as well as any other method, although the potato water is a nice bonus of boiling.

A little more info about potatoes:

http://www.finecooking.com/articles/best-potatoes-to-mash-bake-or-boil.aspx