As food historian Lynne Olver notes on her wonderful site, FoodTimeline.org, coffee cakes like these weren’t invented, they evolved. Sweet cakes made to be served with coffee first began to appear in the 17th century, when coffee was introduced to Northern Europe. But this style of cake, enriched with sour cream and bisected by a layer of streusel, became especially popular in the United States in the 1950s and 1960s and remains a favorite today.
1/3 cup chopped walnuts
1/3 cup firmly packed light brown sugar
1 teaspoon ground cinnamon
2 cups sifted all-purpose flour
1 teaspoon baking powder
1 teaspoon baking soda
1/2 teaspoon table salt
1/2 cup salted butter, softened, plus more for pan
1 cup granulated sugar
2 large eggs
1 teaspoon vanilla extract
1 cup sour cream
Preheat the oven to 350° and grease a 6-cup tube pan. Set aside.
Make the topping: Stir together the walnuts, brown sugar, and cinnamon and set aside.
Whisk the flour with the baking powder, baking soda, and salt until well combined. Cream the butter with the sugar until the mixture is fluffy and light, 3 to 4 minutes, then beat in the eggs and vanilla. Add the flour mixture in alternate thirds with the sour cream, beating well after each addition.
Spoon half the batter into the pan and sprinkle with half the topping, then add remaining batter and sprinkle on the rest of the topping. Bake for 40 minutes without opening the oven, then test for doneness (a toothpick should come out clean) and bake for an additional 5 to 10 minutes, if needed.