I modified this from Samantha Seneviratne's recipe in the NYTimes for "Rhubarb Quick Bread." Mostly I halved it and made some tiny tweaks from reader comments. I made it in my twinkie-shaped little cakes pan. I filled 5 twinkie molds, but should have used six more sparingly. Original recipe here
4 T melted butter
100g sugar
1.5 t freshly grated orange zest
2.5 T sour cream
1 egg
1/2 t vanilla
112g all-purpose flour
1/2 t baking powder
1/4 t baking soda
pinch of salt
1 c rhubarb (about 4 oz), cut into 1/4 inch cubes; I used a slightly heaping cup
turbinado sugar
Oven to 350; grease & flour your pan (or use baking spray).
Whisk butter, sugar, zest, and sour cream, then whisk in eggs. Separately, mix the dry ingredients. Mix rhubarb into dries and then fold dries into wets. Smooth into pan. Sprinkle with turbinado sugar. Bake until skewer comes out clean with moist crumbs attached. (25-30 min? I'm not sure I checked the time). Cool in pan 10 minutes, then turn out.