Another Use for Sumac!: Blackberry Crumb Cake with Sumac Crumb

I bought some sumac (which we don't otherwise use in our household) so I could make Rose Wilde's Pucker-Doodles, and I had a lot of sumac left over after baking the cookies. I didn't have any plans for it -- I mean, what were the chances I would find another recipe using sumac? But I came across one quite by accident as I was flipping through Yossy Arefi's Snacking Cakes. Arefi says the sumac in her "Rhubarb Crumb Cake with Sumac Crumb" gives the topping a "tart and fruity vibe" but suggests lemon zest as a substitute if you don't have sumac. While I didn't have any fresh or frozen rhubarb, I did have some blackberries in the fridge, so I decided to make the berry variation of the recipe.

 

To make the cake, you whisk lemon zest with brown sugar and eggs until pale; add sour cream, melted butter, vanilla, and salt; incorporate flour, baking powder, and baking soda; and fold in the fruit. I poured the batter into a parchment-lined 9-inch round pan and sprinkled on a topping made from flour, brown sugar, oats, sumac, and salt. 

I enjoyed this cake, but mostly what I tasted was just the berries and the crumb topping -- the actual cake was moist but the flavor was not that memorable. As for the sumac crumb, the sumac did give it a slightly unusual flavor that I think many people would not be able to identify. But the oat texture and sweet flavor of the topping were great. Arefi suggests serving the cake with vanilla ice cream, lightly sweetened whipped cream, or heavy cream with whipped with crème fraîche -- I think that any of those would be fantastic and I make this cake again, I would definitely serve it with one of those accompaniments.

Recipe: "Rhubarb Crumb Cake [Berry Crumb Cake variation]," from Snacking Cakes by Yossy Arefi.