I recently started doing an old time favorite of mine, baking cakes with steam instead of oven heat. If you have not tried this you really should, the cake comes out so moist it's well worth the effort.
All you need is a pot, pan, anything you can heat some water in, drop something in to hold the cake above the water level a few inches (you can use cans with rocks in the bottom for weight) and a cover for said pot or pan. At work I used a chafing pan, we put one on the stove Friday night to hold our prime rib. I used a cooling rack to support the cake pan, worked beautifully. I realize most people don't have a chafing pan, but even a roasting pan with lid can be used. Most of the time I use a stockpot since most are fairly deep. You do need something that when covered isn't right on top of the cake if your pan or pot is tall enough you can even cover it with foil. The lid or cover need not fit tightly, as long as you use several inches of water in pan so it doesn't go dry, some steam loss is not important.
After assembling your steaming chamber on the stove and heating up, mix your cake batter as you normally would, I still grease and flour my pan altho only greasing may be needed, I've never tried it without the flouring. Place pan in cteaming chamber, walk away, if you have intense steam coming off you can lower the heat a bit so as not to boil the pan dry. This method usually take as long as baking with heat but one of the pluses is you don't get a hard edge as with baking so it's not a battle to get someone to eat an edge piece lol.
OK, there ya go, give it a try and see, this can also be done over an open fire outside, what a great way to make a dessert camping out, I usually take the canned frosting, warm it up and glaze the cake with it, some reason it's better than icing the cake and you don't run the risk of ripping a section out like frosting a cake with a knife. LoL, remember those old commercials where the housewife was frosting a cake with a paper knife? Anyways, enjoy, I recently did a pumpkin bread mix this way, it was sooooooo moist, so yes, you can do your pumpkin and zucchine breads this way too.