Entenmann’s has nothing on Cook’s Illustrated! I was watching some recorded episodes of America’s Test Kitchen and saw this incredible crumb cake being made. Crumb cake has been on my “to make” list for some time now, as I just can’t resist the light, fluffy cake topping with that sweet crumb topping. It was perfect timing because I was looking for something to make for our monthly neighborhood “Girls Night”. Although the recipe states that it serves 8-10, since I was bringing it for a crowd, I cut the cake into 16 pieces and placed each of them in a cupcake liner for easy consumption. I thought the presentation was so cute, and the cake was definitely a hit. My mom had a piece the next day and said that these rank in the Top 3 things I have ever made. Now that’s a compliment! I stowed away a couple of pieces for myself before I left, but in all honesty, I probably could have eaten this whole cake myself.
For the Crumb Topping
1/3 cup granulated sugar (2 2/3 ounces)
1/3 cup dark brown sugar (2 2/3 ounces)
3/4 teaspoon ground cinnamon
1/8 teaspoon table salt
8 tablespoons unsalted butter (1 stick), melted and still warm
1 3/4 cups cake flour (7 ounces)
For the Cake
1 1/4 cups cake flour (5 ounces)
1/2 cup granulated sugar (3 1/2 ounces)
1/4 teaspoon baking soda
1/4 teaspoon table salt
6 tablespoons unsalted butter (3/4 stick), cut into 6 pieces, softened but still cool
1 large egg
1 large egg yolk
1 teaspoon vanilla extract
1/3 cup buttermilk
Confectioners' sugar for dusting
1. To make the Topping: Whisk sugars, cinnamon, salt, and butter in medium bowl to combine. Add flour and stir with rubber spatula or wooden spoon until mixture resembles thick, cohesive dough; set aside to cool to room temperature, 10 to 15 minutes.
2. To make the Cake: Adjust oven rack to upper-middle position and heat oven to 325 degrees. Cut 16-inch length parchment paper or aluminum foil and fold lengthwise to 7-inch width. Spray 8-inch square baking dish with nonstick cooking spray and fit parchment into dish, pushing it into corners and up sides; allow excess to overhang edges of dish.
3. In bowl of standing mixer fitted with paddle attachment, mix flour, sugar, baking soda, and salt on low speed to combine. With mixer running at low speed, add butter one piece at a time; continue beating until mixture resembles moist crumbs, with no visible butter chunks remaining, 1 to 2 minutes. Add egg, yolk, vanilla, and buttermilk; beat on medium-high speed until light and fluffy, about 1 minute, scraping once if necessary.
4. Transfer batter to baking pan; using rubber spatula, spread batter into even layer. Following photos below, break apart crumb topping into large pea-sized pieces and spread in even layer over batter, beginning with edges and then working toward center. Bake until crumbs are golden and wooden skewer inserted into center of cake comes out clean, 35 to 40 minutes. Cool on wire rack at least 30 minutes. Remove cake from pan by lifting parchment overhang. Dust with confectioners' sugar just before serving.
Note: Don't be tempted to substitute all-purpose flour for the cake flour, as doing so will make a dry, tough cake. If you can't find buttermilk, you can substitute an equal amount of plain, low-fat yogurt. When topping the cake, take care to not push the crumbs into the batter. This recipe can be easily doubled and baked in a 13 by 9-inch baking dish. If doubling, increase the baking time to about 45 minutes. Cooled leftovers can be wrapped in plastic wrap and stored at room temperature for up to 2 days.