The sweet custard falls to the bottom of the pan, and the cake rises to the top, with a layer of tart rhubarb in between.

1 (18.25 ounce) box Duncan Hines white cake mix
    (or any kind that requires oil as an ingredient)
1/4 teaspoon freshly ground nutmeg (optional)
3 cups diced rhubarb, cut into 1/2-inch pieces
1 1/2 cups granulated sugar
1 pint whipping cream

Preheat oven according to cake package directions. Cut rhubarb into pieces and set aside.

Prepare cake as directed on package, using an 11 x 15-inch baking pan. Add nutmeg to batter, if desired. Pour batter into pan.

At the last minute, toss the sugar with the rhubarb and sprinkle over the cake batter. Drizzle the entire pint of whipping cream over the batter and fruit; do not mix it in.

Bake about 35 minutes, or until the top of the cake turns a light golden brown and begins to leave the sides of the pan. A wooden pick inserted into the cake part should come out clean.