Nigella Lawson's Toasted Marshmallow and Rhubarb Cake

Photo: Jonathan Lovekin

Serves: 8 to 12 slices

This is a relatively new addition to my rhubarb repertoire, but it has been heavily in rotation ever since I first made it nearly two years ago. Anyone who has a birthday when the hothouse pink rhubarb is in season gets it (and I do even have alternatives for those dim days when it isn’t, and I’ll get to them …