I've been thinking about the handful of fruits and vegetables that we use in cooking but would never pop into our mouths, fresh. I mean to say, foods that require a significant transformation for them to be edible, like olives, rhubarb and cranberries. Olives have to be fermented or cured, rhubarb has toxic leaves and is almost always macerated, and then baked. And cranberries — have you ever tried to just eat a cranberry? Not pleasant. And acorns. It has never even occurred to me to eat an acorn. Yet, it is a nut. Squirrels eat acorns. And throughout history acorns have been ground up to make grain flours and even used as a coffee substitute for soldiers in both the Civil War and World War II.
It fascinates me to no end to think of the trajectory of how we, the people, figured out how to make these things (and all things) edible. “Well, Hyram there died when he ate that acorn. So let's try and soak it in another poisonous substance, LYE, and give it another go. Yes? Rodney's okay? All right, good to hear, because this would make a lovely flour with which to create a noodle.”
Rhubarb. It comes into season in the spring, and everyone gets all aflutter about it. I'd say about ninety percent of the time you'll find rhubarb paired with strawberries and baked into a pie or a crumble. It's bright, tart and guaranteed to make you pucker up.
I have always really loved coffee cakes and pound cakes. They’re less cake-like and more akin to very sweet breads. Interestingly, both are also Southern. To this day, I would eat the Tasty Cake version of a coffee cake or the Sarah Lee version of a pound cake in a hot minute. The most beguiling part of coffee cake is the crumb topping. Those brown, sugary, buttery grape-sized chunks on top of the cake that are toothachingly, cloyingly sweet — that almost requires a swallow of coffee to allay the sweetness – that's my jam.
And what better element to cut that sweetness than the tartness of rhubarb? In this recipe, the rhubarb, which had been macerated prior to baking, is mellow and gently sweet, but maintains its pert zing, adding an ideal offset to the sugar-bomb, crumb-y coffee cake. Well, that and a cup of hot coffee.
Rhubarb Crumb Coffee Cake
Serves 8For the rhubarb filling:
1/2 pound of rhubarb, trimmed
1/4 cup of sugar
2 teaspoons of cornstarch
1/2 teaspoon of fresh, grated gingerFor the crumbs:
1/3 cup of dark brown sugar
1/3 cup of sugar
1 teaspoon of ground cinnamon
1/2 teaspoon of fresh, grated ginger
1/8 teaspoon of salt
1/2 cup (1 stick) of butter, melted
1 3/4 cups of all-purpose flourFor the cake:
1/3 cup of plain Greek yogurt
1 large egg
1 large egg yolk
2 teaspoons of vanilla extract
1 cup of all-purpose flour
1/2 cup of sugar
1/2 teaspoon of baking soda
1/2 teaspoon of baking powder
1/4 teaspoon of salt
6 tablespoons of softened butter, cut into 8 pieces.
Preheat the oven to 325 degrees. Grease an 8-inch baking pan. For the filling, slice the rhubarb 1/2 inch thick and toss with the sugar, cornstarch and ginger. Set aside.
To make the crumbs, whisk the sugars, spices and salt into melted butter in a large bowl until smooth. Then, add the flour with a spatula or wooden spoon, stirring. It will look and feel like solid dough. Leave it pressed together in the bottom of the bowl and set aside.
To prepare the cake, stir together the yogurt, egg, egg yolk and vanilla in a small bowl. Using a stand mixer fitted with paddle attachment, mix together the flour, sugar, baking soda, baking powder and salt. Add the butter and a spoonful of sour cream mixture and mix on medium speed until the flour is moistened. Increase the speed and beat for 30 seconds. Add the remaining sour cream mixture in two batches, beating for 20 seconds after each addition, scraping down the sides of the bowl with a spatula. Scoop out about 1/2 cup of batter and set aside.
Scrape the remaining batter into prepared pan. Spoon the rhubarb over the batter. Dollop the remaining batter over the rhubarb; it does not have to be even.
Using your fingers, break the topping mixture into big crumbs, about 1/2 inch to 3/4 inch. They don’t have to be uniform, but make sure most are around that size. Sprinkle them over cake. Bake the cake until a toothpick inserted into center comes out clean (it may still be moist from rhubarb), 45 to 55 minutes. Cool completely before serving.