Soft buttermilk cake loaded with fresh rhubarb & crowned with brown sugar crumb topping.
Prep Time30 minutesmins
Bake Time45 minutesmins
Total Time1 hourhr15 minutesmins
Servings:16portions
Ingredients
Crumb Topping
6 ¾ozcake flour(1 ½ cups, see note)
5 ¼ozbrown sugar(⅔ cup)
¼teaspoonsalt
2teaspoonscinnamon
1teaspoonground ginger
4ozunsalted butter(room temperature)
Cake Batter
1large egg
1yolk
6ozbuttermilk(¾ cup, divided)
1teaspoonvanilla
9ozcake flour(2 cups)
6ozgranulated sugar(¾ cup)
1 ½teaspoonsbaking powder
1teaspoonground ginger
¼teaspoonsalt
4ozbutter(room temperature)
1poundrhubarb(cut into ½" dice (about 3 cups))
Instructions
Preheat the oven to 350 °F. Butter and flour a 9" square cake pan. Cut an 8"x16" piece of parchment paper and line the pan in one direction, leaving a short overhang on each side.
Crumb Topping
Combine 6 ¾ oz cake flour, 5 ¼ oz brown sugar, ¼ teaspoon salt, 2 teaspoons cinnamon, and 1 teaspoon ground ginger into the bowl of a stand mixer or into a large mixing bowl. Mix on low speed until completely combined. With the mixer running, add 4 oz unsalted butter in chunks and continue to mix until the topping looks like wet sand. Remove from the mixer and transfer to a small bowl by squeezing handfuls to create large clumps. Set aside while you mix the batter.
Batter
Combine 1 large egg, 1 yolk, 6 oz buttermilkalf the buttermilk and 1 teaspoon vanilla in a small bowl and set aside.
Sift 9 oz cake flour, 6 oz granulated sugar, 1 ½ teaspoons baking powder, 1 teaspoon ground ginger, and ¼ teaspoon salt into the bowl of a stand mixer or into a large mixing bowl. With the mixer running on low speed, add 4 oz butter and the remaining buttermilk. Mix until completely combined. Scrape the bowl and beater. Mix on medium speed for 2-3 minutes to lighten the batter.
Scrape the bowl and add the egg mixture in two batches, scraping between additions. Remove 1 cup of the batter and spread it into the pan. By hand, fold the rhubarb into the remaining batter. Spread the batter with the rhubarb into the pan.
Sprinkle the crumb topping over the batter, breaking it into marble sized clumps as you scatter it over the cake batter.
Bake until a toothpick inserted in the center comes out clean, about 45-50 minutes. Cool at least 30 minutes in the pan. Use the parchment to carefully lift the cake out of the pan.
Cool completely on a wire rack
Notes
If measuring the flour by volume use the “dip & sweep” method. That is, dip the measuring cup into the flour bin, overfill it, then sweep away the excess.