Makes: 8 to 10 servings
Time: About 1 hour, 15 minutes
Buckle is where cake meets pie. It’s a great way to highlight summer fruit in a cake without sacrificing the best part of pie: streusel topping. The cake will fall a bit while cooling, but don’t be alarmed. This is normal.
1. Heat the oven to 350°F. Grease and flour the bottom and sides of an 8- or 9-inch cake pan or springform cake pan, or a 13 × 9-inch sheet pan.
2. Whisk together the flour, baking powder, salt, and cinnamon if you’re using it in a medium bowl and set aside. In a large bowl, use an electric mixer to cream the butter and sugar until smooth. Add the egg and beat until light and fluffy.
3. Stir about half the flour mixture into the batter by hand, then add the milk, then the rest of the flour. Stir gently until combined. Fold in the blackberries.
4. Turn the batter into the prepared pan and sprinkle with the streusel topping. Bake until the cake is golden brown and a toothpick inserted into the center comes out clean or with a few moist crumbs, about 1 hour. Let cool for about 15 minutes, then turn the cake out onto a rack to finish cooling. You can also slice and serve the cake straight from the pan. Store at room temperature, covered with plastic wrap, for up to a few days.
CHERRY-VANILLA BUCKLE You can use sweet or sour cherries, as you prefer: Substitute pitted and chopped cherries for the blackberries. Stir 1 tablespoon vanilla extract into the batter after you add the eggs.
PEACH-GINGER BUCKLE Sweet and spicy: Substitute 3 to 4 chopped peaches for the blackberries and 1 teaspoon ground ginger for the cinnamon. Fold in ¼ cup chopped candied ginger with the peaches.
PLUM-THYME BUCKLE The delicate flavor of plums pairs well with the savory herb: Substitute 4 or 5 chopped plums for the blackberries. Toss 2 tablespoons chopped fresh thyme into the streusel topping.
BLUEBERRY-CARDAMOM BUCKLE Substitute blueberries for the blackberries and 2 teaspoons cardamom for the cinnamon.