2 cups all-purpose flour
1 teaspoon baking powder
1 teaspoon baking soda
½ teaspoon kosher salt
½ cup unsalted butter, at room temperature
1½ cups granulated sugar, divided
2 eggs, at room temperature
1 cup sour cream, at room temperature
1 teaspoon vanilla extract
1 teaspoon ground cinnamon
3 large, ripe peaches, peeled, pitted, and sliced
½ cup chopped pecans
1. Preheat the oven to 350 degrees F. Grease a 9-inch square baking pan.
2. In a medium bowl, whisk together the flour, baking powder, baking soda and salt; set aside.
3. Using an electric mixer, beat the butter and 1 cup of the sugar for 3 to 5 minutes on medium-high speed, until light and fluffy. Reduce the mixer speed to low and add the eggs one at a time, beating well after each addition. Add the sour cream and vanilla, and mix until the batter is smooth. Slowly add the dry ingredients to the batter and mix just until combined, using a rubber spatula to fold in any flour that needs to be incorporated.
4. In a small bowl, combine the remaining ½ cup sugar and the cinnamon.
5. Spread half of the batter evenly into the bottom of the pan. Top with half of the peaches, then sprinkle with two-thirds of the cinnamon sugar. Drop the remaining batter on top of the peaches in small mounds, then use an offset spatula to gently spread it into an even layer, covering the peaches. Arrange the remaining peaches on top and sprinkle with the remaining cinnamon sugar and the pecans.
6. Bake the cake for 45 to 55 minutes, until a toothpick inserted in the center comes out clean. Serve warm or at room temperature.