Instead of using a cast-iron skillet, you can make the buckle in a 9-inch square baking pan or in a 2-quart shallow baking dish. Serve straight from the pan.
- 1/2 cup (1 stick) unsalted butter, softened, plus more for skillet
- 3/4 cup plus 2 tablespoons sugar
- 3 large eggs
- 1 teaspoon vanilla extract
- 1 1/4 cups all-purpose flour (spooned and leveled)
- 1/4 teaspoon baking powder
- 1/2 teaspoon salt
- 1 1/2 pounds peaches, pitted, peeled, and cut into 1/2-inch pieces (4 cups)
- 1/2 teaspoon ground cinnamon
- 1/3 cup sliced almonds
Preheat oven to 350 degrees. Butter a 10-inch cast-iron skillet, 9-inch square baking pan, or 2-quart shallow baking dish. In a large bowl, cream butter and 3/4 cup sugar with an electric mixer until fluffy. Add eggs, one at a time, and vanilla; beat to combine.
In a medium bowl, whisk together flour, baking powder, and salt. With mixer on low speed, gradually add flour mixture to butter mixture; beat until incorporated. Fold in peaches.
Spread batter in prepared skillet. In a small bowl, mix together remaining 2 tablespoons sugar, cinnamon, and almonds. Sprinkle mixture over top; bake until a toothpick inserted in center comes out clean and topping is golden, 45 to 50 minutes. Let cool 20 minutes before serving.