Apple-Prune Crumb Cake Squares


Crumb topping:
13/4 cups all-purpose flour
1/4 cup granulated sugar
1/3 cup light brown sugar
1 teaspoon ground cinnamon
1/2 teaspoon ground ginger
1/4 teaspoon salt
1/2 cup walnut halves or pieces, about 2 ounces
12 tablespoons (11/2 sticks) unsalted butter, melted

Fruit mixture:
12 moist plump large prunes, about 8 ounces
3 Golden Delicious apples, about 11/2 pounds 
1/2 cup coarsely chopped walnuts, about 2 ounces
1/3 cup granulated sugar
1 tablespoon fresh lemon juice

13/4 cups all-purpose flour
11/2 teaspoons baking powder
1/4 teaspoon salt
12 tablespoons (11/2 sticks) unsalted butter, softened
11/2 cups granulated sugar
3 large eggs, at room temperature
1 teaspoon vanilla extract

Sweetened sour cream garnish:
2 cups sour cream
1/2 teaspoon vanilla extract
3 tablespoons mild-flavored honey

Confectioners’ sugar for dusting


1. Make crumb topping: Put flour, granulated sugar, light brown sugar, cinnamon, ginger, salt and walnuts in bowl of food processor fitted with metal chopping blade. Pulse until nuts are finely ground. Transfer mixture to large mixing bowl. Add melted butter and mix with fork until dry ingredients are uniformly moistened and mixture starts to clump together. Set aside. 

 2. Make fruit mixture: Remove pits from prunes. Using pair of scissors, cut prunes into 1/2" pieces. There will be about 11/4 cups cut up prunes. Set aside.

3. Peel, quarter and core apples. Cut each quarter crosswise into 1/4" slices. Put apple slices, prunes and walnuts in large mixing bowl. Add sugar and lemon juice and toss to combine.

4. Make cake: Position rack in center of oven and preheat to 350°F. Butter bottom and sides of 101/2" x 151/2" x 1" jelly roll pan.

5. In medium-size bowl, whisk together flour, baking powder and salt until well-blended. Set aside.

6. In bowl of electric mixer, using paddle attachment, beat together butter and sugar on medium speed for about 3 minutes, or until light and fluffy. Add eggs, one at a time, beating well after each addition and stopping to scrape down sides of bowl as necessary. Beat in vanilla. On low speed, add flour mixture in 2 additions and mix just until flour is absorbed. Scrape batter into prepared pan and smooth top with small offset metal spatula. Spread fruit mixture evenly over batter. Sprinkle crumb topping evenly over fruit mixture, breaking up any large crumbs with your fingers.

7. Bake cake for about 45 minutes, or until center is firm. Transfer cake in pan to wire rack and cool completely.

8. Make sweetened sour cream: Combine sour cream, vanilla and honey in medium-size bowl and whisk until well-blended. Cover with plastic wrap and refrigerate until chilled.

9. To serve, cut cake into 15 squares and dust with confectioners’ sugar. Place each square on dessert plate and garnish with dollop of sweetened sour cream. (For more casual entertaining, pile cake squares on flat serving platter and pass around sour cream in sauceboat.)