Ingredients

For the Nut Filling:
• 3/4 cup dark brown sugar, firmly packed
• 1 tablespoon cinnamon
• 1 tablespoon unsweetened cocoa powder
• 2-3 tablespoons currants or raisins, coarsely chopped
• 3 1/2 ounces (1 cup) walnuts, finely chopped
For the Cake Batter:
• 3 cups all purpose flour
• 1 1/2 teaspoons double acting baking powder
• 1 1/2 teaspoons baking soda
• 1/2 teaspoon salt
• 6 ounces unsalted butter, at cool room temp
• 2 teaspoons vanilla extract
• 1 1/2 cups sugar
• 3 eggs
• 2 cups sour cream
For the Glaze:
• 2 cups powdered sugar
• 1 teaspoon vanilla extract
• 2-3 tablespoons hot milk

Instructions

For the Filling:
1. In a small bowl, stir the brown sugar, cinnamon and cocoa to mix thoroughly. Stir in the currants or raisins, then the walnuts, and set aside.
For the Cake Batter:
2. Adjust the rack one-third up from the bottom of the oven. Preheat the oven to 375 degrees. Butter the pan well - Ms. Heatter points out that even if the pan is Teflon coated, it must be buttered.
3. Whisk together the flour, baking powder, baking soda, and salt, Set the mixture aside.
4. In the large bowl of an electric mixer, cream the butter. Add the sugar, and vanilla, beating at medium speed for a minute of two, until light.
5. Add the eggs, one at a time, beating until thoroughly incorporated after each. Scrape down the bowl, and beat briefly at high speed for a minute or tow until the mixture is very smooth.
6. Alternately add the dry ingredients in three additions and the sour cream, in two additions, on low speed, beating until only smooth after each addition.
7. Spread a thin layer of batter in the bottom of the pan. Sprinkle generously with one-third of the nut filling. Continue with the layering of nut filling and batter, dropping small spoonfuls of batter over the filling, then spreading with the back of a spoon.- three or four layers. Ms. Heatter advises that it takes bit of patience to spread the batter thinly. The top layer should be batter.
8. Bake for about an hour, until a toothpick or cake tester, comes out dry, and the top feels firm and springy. As always, the cake may take a bit longer or shorter depending on your pan and oven. Be sure it is done.
9. Remove it from the oven when it's done. Leave the cake in the pan for 5 minutes, no longer. The cake should still be hot when the glaze is applied.
For the glaze:
10. In a small bowl, mix with a rubber spatula or lightly whisk together the powdered sugar, vanilla and about 2 tablespoons of the hot milk. Very gradually add more milk, using only enough to make a slightly fluid mixture, about as thick as a thick cream sauce.
11. Cover a cake rack with a large piece of wax paper, and invert the cake in the pan onto the rack. Alternately, you can invert the cake onto a cardboard cake circle, then set the cake round onto the rack. Remove the pan. Immediately pour the glaze onto the cake, without spreading it, just letting it run down the sides.
12. When the glaze has set, use a large spatula or two to transfer the cake to a plate. The cake is excellent either still warm or the next day.