Maple-Walnut Crumb Cake (gluten-free)
3/4 cup firmly packed brown sugar
1/3 cup gluten-free flour
3/4 cup finely chopped walnuts
1/4 cup (4 tablespoons) unsalted butter cut into small pieces
2 cups gluten-free flour (I used Cup 4 Cup brand which includes xanthan gum)
1-1/2 teaspoons baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
1 cup (2 sticks) unsalted butter, softened
1 cup firmly packed dark brown sugar
2 large eggs
1/3 cup maple syrup (I used Grade B, which is darker and richer tasting)
1/2 teaspoon vanilla extract
7 tablespoons milk (I used skim milk, but whole milk is called for)
1) Heat oven to 350 degrees F. Grease a 9" square baking pan with butter or nonstick cooking spray.
2) To make the streusel, whisk brown sugar and flour well in a small bowl, then stir in walnuts. Using your fingers, work in the pieces of butter until evenly combined and mixture starts to come together. Set aside.
3) Make the batter: in a medium bowl, whisk together flour, baking powder, baking soda and salt until combined. Set aside.
4) In the bowl of an electric mixer, cream butter and dark brown sugar on medium until light and fluffy, about 3 minutes. Add the eggs, one at a time, beating well after each addition. Scrape down sides of bowl. Stir in maple syrup and vanilla.
5) Alternately add the flour mixture and milk to the butter mixture, starting and ending with the flour mixture, stirring between each addition until blended.
6) Spoon half the batter into prepared pan and spread evenly. Sprinkle half the streusel mixture over the batter. Top with remaining batter and spread until smooth.* Crumble the remaining streusel over the top.
7) Bake until golden brown until a wooden pick inserted in the center comes out clean, 40 to 50 minutes (mine baked for 45 min.). Let the cake cool about 10 minutes before serving, or let cool to room temperature.
* Note: I found the batter was very sticky. I'm not sure if this is typical, or if I overmixed the batter, but I had a hard time spreading it on the bottom of the pan and had to use my fingers. The same was true of the remaining batter that goes over the streusel filling. To prevent it from mixing together, I dolloped the batter in clumps and used my fingers to "spread" it. In the oven, however, the cake filled in beautifully and the final product was perfect.