The cooking newsgroup I lurk/post raves about this recipe. I’ve made it (it was my one and only experience with rhubarb so far) and liked it, it maintains a nice sweet/tartness and the custard layer is a good contrast.
Be careful if you’re using those Baker’s Secret/Ecko nonstick baking pans, the acidity can strip the nonstick finish right off. Ask me how I know this. [:p]
Rhubarb Custard Cake
By Barb S. on rec.food.cooking
2-layer boxed yellow or white cake mix (I like yellow; the kind that
requires the addition of butter, too.)
4 cups cut rhubarb (1/2" pieces, maybe?)
1 cup sugar
1 pint (2 cups) whipping cream
Make cake batter according to package directions and pour into greased
and floured 9×13" cake pan. Dump the prepared rhubarb on top, evenly.
Sprinkle the sugar evenly over the rhubarb. Pour the whipping cream
over all of it. Bake at 350 deg F for about 45-55 minutes, until cake
portion tests done. What happens is the fruit, sugar, and whipping
cream sink to the bottom of the batter and make this yummy creamy
custardly layer. To die for. When you cut and serve it, flip it over
and serve custard side up.