- 1 ½ cups pecans, finely chopped
- ⅓ cup white sugar
- ⅓ cup packed light brown sugar
- 3 tablespoons melted butter
- 1 teaspoon cinnamon
- ⅛ teaspoon salt
- 1 ⅞ cups all-purpose flour
- 1 teaspoon baking powder
- ¾ teaspoon baking soda
- ½ teaspoon fine sea salt
- 1 cup white sugar
- ½ cup unsalted butter, softened
- 2 large eggs
- 1 cup sour cream or creme fraiche
- 1 ½ teaspoons vanilla extract
- Preheat the oven to 350 degrees F (175 degrees C). Butter an 8×10-inch baking dish.
- Make the topping: Mix pecans, white sugar, brown sugar, melted butter, cinnamon, and salt together in a mixing bowl until thoroughly combined and all components are coated with butter, 3 to 4 minutes.
- Make the cake: Whisk flour, baking powder, baking soda, and salt together in a medium bowl.
- Mix sugar and butter together in a large bowl with a spatula until well blended. Whisk in eggs, one at a time, until thoroughly incorporated. Whisk in sour cream and vanilla. Gradually whisk in flour mixture until flour is just incorporated; do not overmix.
- Spread 1/2 of the batter over the bottom of the prepared baking dish, then sprinkle with 1/2 of the topping. Carefully spoon remaining batter over topping, then sprinkle with remaining topping; very gently press topping into batter.
- Bake in the preheated oven until a bamboo skewer inserted into the center comes out clean, 30 to 35 minutes. Let cool slightly before serving.