unbleached all-purpose flour
unsalted butter, softened
( 1 1/4 sticks)
egg, at room temperature
walnuts, finely chopped
( or pecans)
- Adjust oven rack to center position and heat oven to 350°.
- Generously grease bottom and lightly grease sides of 10-inch springform pan and dust with flour.
- With electric mixer, mix flour, sugar, and salt in large mixing bowl until blended.
- Cut in butter until mixture resembles coarse crumbs.
- Remove 1 cup of crumbs to separate bowl.
- Mix baking powder and soda into mixture remaining in large mixing bowl.
- Add buttermilk, egg, and vanilla; mix well until batter is thick, smooth, fluffy, and frostinglike, 1 1/2- 2 minutes.
- Using a rubber spatula, scrape batter into prepared pan and smooth top.
- Add nuts, brown sugar, cinnamon and allspice to reserved crumbs; toss with a fork or your hands until blended.
- Sprinkle crumbs over batter, pressing lightly so that mixture adheres.
- Bake cake until center is firm and cake tester comes out clean, 50- 55 minutes. TIP: Do not insert a toothpick to test for doneness until center is firm when pan is shaken.
- Transfer cake to rack; remove pan sides.
- Let cake cool completely, about 2 hours, before serving.
- When completely cooled, cake can be slid off pan bottom onto serving plate.