REC: Gluten-Free Yellow Layer Cake with Creamy Chocolate Frosting from ATK
(also, notes at end about GF flours)
Gluten-Free Yellow Layer Cake
from America's Test Kitchen
Cake layers:
6 Ounces white chocolate
8 Tablespoons unsalted butter
11 Ounces (1¾ cups plus 2/3 cup) ATK Gluten-Free Flour Blend * (see recipe below)
1 Tablespoon baking powder
1¼ Teaspoons xanthan gum (OR 2½ teaspoons psyllium powder)
1 Teaspoon salt
¼ Teaspoon baking soda
4 Large eggs
Pinch cream of tartar
7 Ounces (1 cup) sugar
1½ Tablespoons vanilla extract
2/3 Cup sour cream
Creamy chocolate frosting:
4-2/3 Ounces (2/3 cup) sugar
4 Large egg whites
Pinch salt
24 Tablespoons (3 sticks) unsalted butter
12 Ounces bittersweet chocolate
1 Teaspoon vanilla extract
Instructions
cake:
1. Adjust oven rack to middle position and heat oven to 325 degrees.
2. Grease two 9-inch round cake pans, line bottoms with parchment paper, and grease parchment.
3. Cut 8 tablespoons unsalted butter into 8 pieces.
4. Chop 6 ounces white chocolate.
5. Microwave chocolate and butter in bowl at 50 percent power, stirring occasionally, until melted, about 2 minutes. Whisk mixture until smooth, then set aside to cool slightly.
6. In separate bowl, whisk 11 ounces flour blend, 1 tablespoon baking powder, 1¼ teaspoons xanthan gum, 1 teaspoon salt, and ¼ teaspoon baking soda until combined.
7. Separate 4 large eggs.
8. Using stand mixer fitted with whisk, whip 4 egg whites and pinch cream of tartar on medium-low speed until foamy, about 1 minute.
9. Increase speed to medium-high and whip whites to soft, billowy mounds, about 1 minute.
10. Gradually add ½ cup sugar and whip until glossy, stiff peaks form, 2 to 3 minutes; transfer to bowl.
11. Return now-empty bowl to mixer, add 4 large egg yolks and 1½ tablespoons vanilla, and whip on medium speed until well blended, about 30 seconds.
12. Gradually add remaining ½ cup sugar, increase mixer speed to high, and whip until very thick and pale yellow, about 2 minutes.
13. Reduce mixer speed to medium, add chocolate mixture and 2/3 cup sour cream, and whip until combined, about 30 seconds.
14. Reduce speed to low, slowly add flour blend mixture, and mix until thoroughly combined, about 1 minute.
15. Using rubber spatula, stir 1/3 of whipped egg whites into batter to lighten. Gently fold in remaining whites until no white streaks remain.
16. Divide batter evenly between prepared pans and smooth tops.
17. Bake until cakes begin to pull away from sides of pans and spring back when pressed lightly, 30 to 32 minutes, switching and rotating pans halfway through baking.
18. Let cakes cool in pans on wire rack for 10 minutes. Run knife around edge of cakes to loosen.
19. Remove cakes from pans, discard parchment, and let cool completely on rack, about 1½ hours. (Layers can be wrapped tightly in plastic wrap and stored for 1 day.)
20. FOR FROSTING:
Cut 24 tablespoons (3 sticks) unsalted butter into 24 pieces and let soften on counter.
21. Chop 12 ounces bittersweet chocolate. Transfer to microwave-safe bowl.
22. Melt chocolate and let cool to between 85 and 100 degrees.
23. Combine 2/3 cup sugar, 4 large egg whites, and pinch of salt in bowl of stand mixer; place bowl over saucepan with one inch simmering water.
24. Whisking gently but constantly, heat mixture until slightly thickened and foamy and it registers 150 degrees, 2 to 3 minutes.
25. Place bowl in stand mixer fitted with whisk. Beat mixture on medium speed until consistency of shaving cream and it has cooled slightly, about 5 minutes.
26. Add softened butter, 1 piece at a time, until smooth and creamy. (Frosting may look curdled after half of butter has been added; it will smooth with additional butter.)
27. Once all butter is added, add cooled melted chocolate and 1 teaspoon vanilla and mix until combined.
28. Increase speed to medium-high and beat until light, fluffy, and thoroughly combined, about 30 seconds, scraping beater and sides of bowl with rubber spatula as necessary.
29. If frosting seems too soft after adding chocolate, chill it briefly in refrigerator, then re-whip until creamy.
30. TO ASSEMBLE CAKE: Place 1 cake layer on platter and spread 1½ cups frosting evenly over top using offset spatula.
31. Top with second cake layer, press lightly to adhere, then spread remaining 2½ cups frosting evenly over top and sides. Serve.
NOTE: Best served within a few hours of frosting.
The America’s Test Kitchen Gluten-Free Flour Blend
Makes 42 ounces (about 9 1/3 cups)
Be sure to use potato STARCH, not potato flour. Tapioca starch is also sold as tapioca flour; they are interchangeable. See note below about buying rice flours.
24 ounces (4½ cups plus 1/3 cup) white rice flour
7½ ounces (1 2/3 cups) brown rice flour
7 ounces (1 1/3 cups) potato starch
3 ounces (¾ cup) tapioca starch
¾ ounce (3 tablespoons) nonfat milk powder
Whisk all ingredients together in large bowl until well combined. Transfer to airtight container and refrigerate for up to 3 months.
Gluten-Free Yellow Layer Cake
A good yellow layer cake should melt in the mouth and taste of butter and vanilla. But many gluten-free layer cakes are overly sweet, and most come out dense and gummy. If those problems weren’t daunting enough, all of the published recipes that we tried were terribly greasy.
The standard amount of butter in a traditional yellow layer cake (two sticks) is way too much. The starches in gluten-free flour just don’t absorb fat (especially butter) all that well. We dramatically reduced the amount of butter in our working recipe, but predictably that left the cake too lean and dry. Replacing the milk or buttermilk used in classic recipes with sour cream was a step in the right direction, but we needed more richness. In the end, we borrowed a trick that works for chocolate cakes—melted chocolate—to help solve this problem. Rather than using unsweetened or bittersweet chocolate (neither acceptable in a yellow cake), we turned to white chocolate, and it worked like a charm, boosting richness without making the cake greasy.
With one big problem solved, we now focused on lightening up the crumb. Adding extra baking powder and a bit of baking soda helped give our cake better rise and a tender texture. To create a really fluffy texture, we needed to whip the egg whites with some sugar to create a stable meringue-like mixture that could provide greater lift in the oven. Whipping the egg yolks with a bit more sugar ensured that sufficient air was in the batter.
Note the relatively low oven temperature, which we found allows the layers to cook through without excessive browning. These lofty layers are tender yet sturdy enough to stand up to a thick coating of frosting. We use Creamy Chocolate Frosting in this lesson, but 4 cups of any frosting can be used. While this cake is best served within a few hours of frosting, the cake layers can be made a day in advanced, wrapped tightly in plastic wrap, and stored at room temperature.
