For the shopping list
Rhubarb Stalks (about 2 cups sliced)
Sugar, preferably unrefined cane sugar
* make a buttermilk substitute by adding a tablespoon of cider vinegar or lemon juice with a scant 1 ½ cups plain milk
From the kitchen
Skillet or Cake Pan
I cook this cake in a 12-inch cast iron skillet, but you can use a cake pan. For the skillet, cut a piece of parchment to fit the bottom and drizzle some oil into the skillet before you put it in.
Preheat the oven to 350F.
Slice the rhubarb into roughly half-inch pieces. Toss it with a tablespoon of sugar and set aside.
Beat the eggs in a large bowl, then add the sugar and stir well. Whisk in the milk next and stir until completely mixed in, then add the olive oil and stir again.
In another bowl, stir together the flour, baking powder, and salt. Make a well in the dry ingredients, and slowly add the egg mixture, stirring just until blended. Do not over mix.
Pour the batter into the prepared skillet.
Carefully add the sliced rhubarb in an even layer across the top. It’ll sink into the batter a bit, but that’s fine
Bake until a toothpick inserted into the center comes out clean, 50 to 55 minutes. Let the cake cool in the skillet and serve it from the pan, or carefully invert onto a plate when it’s completely cool. If you're feeling fancy, add a dollop of whipped cream, creme fraiche, or yogurt just before serving.