Classic Crumb Cake

From Martha Stewart

Cybele Pascal shares an allergen-free recipe for classic crumb cake.

Whether they have food allergies or not, everyone will love this delicious allergen-free crumb cake.

This recipe reprinted with permission from "The Allergen-Free Baker's Handbook," by Cybele Pascal (Celestial Arts; 2009).

Makes 12 servings

Ingredients
For the cake
        1/2 cup dairy-free, soy-free vegetable shortening, room temperature, plus more for baking pan
        2 cups Basic Gluten-Free Flour Mix, plus more for baking pan
        1/2 teaspoon xanthan gum
        1 teaspoon double-acting baking powder
        1 teaspoon baking soda
        1 teaspoon salt
        1 cup coconut milk vanilla yogurt
        1 teaspoon cider vinegar
        1 tablespoon Ener-G egg replacer
        1/4 cup rice milk
        1 cup granulated sugar
        1 teaspoon pure vanilla extract
        Confectioners' sugar, for dusting
   
For the crumb topping
        3/4 cup Basic Gluten-Free Flour Mix
        1/4 teaspoon xanthan gum
        1/4 teaspoon coarse salt
        1/2 cup firmly packed light-brown sugar
        1/2 teaspoon ground cinnamon
        1/4 cup dairy-free, soy-free vegetable shortening, chilled and cut into tablespoon-size pieces

Method
Make the crumb topping: In a medium bowl, whisk together flour mix, xanthan gum, and salt. Add sugar and cinnamon; whisk to combine. Add chilled shortening and, using a pastry blender or two knives, blend to form pea-sized crumbs; set aside.
   
Make the cake: Preheat oven to 325°F. Coat a 9-by-9-inch square baking pan with shortening and dust with some of the flour mix, tapping out excess.
   
In a large bowl, whisk together flour mix, xanthan gum, baking powder, baking soda, and salt; set aside. In a medium bowl, mix together yogurt and vinegar; set aside. Mix together egg replacer and rice milk; set aisde.
   
In the bowl on electric mixer fitted with the paddle attachment, mix together shortening, sugar, egg replacer mixture, and vanilla; beat on medium speed until light and fluffy, about 2 minutes. Add flour mixture in three additions, alternating with the yogurt mixture and beginning and ending with the flour mixture. Beat until just combined, scraping down sides of bowl as necessary.
   
Pour batter into prepared pan, smoothing surface with a spatula. Sprinkle crumb topping over top, using your finger to clump some of the topping together to form larger crumbs. Transfer to oven and bake until the top of cake is golden and springs back when touched lightly, about 45 minutes.
   
Let cool in pan on a rack for about 15 minutes. Invert cake onto a large plate, cover with a cooling rack, and reinvert onto the rack, crumb-side up. Let cool completely. Sift confectioners' sugar over the top and cut into squares. Cake may be stored in an airtight container at room temperature, up to 3 days.