- ½ cup/113 grams unsalted butter at room temperature
- 1 ¼ cups/260 grams sugar
- 2 large eggs
- 1 ½ cups flour/188 grams
- 1 ½ teaspoons baking powder
- ½ teaspoon baking soda
- ½ teaspoon salt
- 1 ¼ cups/300 grams sour cream
- 1 teaspoon vanilla
- ½ cup packed dark brown sugar
- ¼ cup all-purpose flour
- 1 tsp ground cinnamon
- 3 Tbsp unsalted butter, melted
- ¾ cup chopped walnuts (which I roast in advance)
- Preheat oven to 350 degrees and generously butter a 9-by-13-inch baking pan. Cream butter and sugar together until light and fluffy. Add eggs one at a time, beating well after each addition.
- In a separate bowl, sift flour with baking powder, baking soda and salt. With the mixer on low speed, add the flour mixture to the butter mixture alternately with sour cream and vanilla until just combined. Do not overmix. Pour batter into prepared baking pan.
- Make the topping: Combine sugar, cinnamon, flour and nuts in a small bowl and mix well.
- Sprinkle the topping evenly over the cake and bake 30 to 35 minutes, or until a cake tester comes out clean. Cool, cut into pieces and serve.
Adapted from Robert Farrar Capon