A buttermilk-based tender nectarine crumb cake that's full of fresh nectarines to make the most of stone fruit season. This is a lovely little breakfast cake or dress it up with a scoop of vanilla ice cream for dessert.
1 ¼cupsoat flour, or 1 cup whole wheat pastry flour
½teaspoonbaking powder
½teaspoonbaking soda
¼teaspoonsalt
¼cupunsalted butter, at room temperature
⅔cupsugar
½teaspoonpure vanilla extract
½cupwell-shaken buttermilk
4nectarines, pitted and coarsely chopped
For the Crumb Topping
¼cupold fashioned rolled oats
2tablespoonssugar
¼cupoat flour
2tablespoonsunsalted butter, at room temperature
Instructions
Preheat oven to 400°F with rack in middle. Butter and flour a 9-inch round cake pan.
Make the topping
In a small bowl, whisk together the oats, sugar, and flour. Rub in the butter with your hands until it forms a coarse meal.
Make the cake
Whisk together flour, baking powder, baking soda, and salt.
Beat butter and ⅔ cup sugar with an electric mixer at medium-high speed until pale and fluffy, about 2 minutes, then beat in vanilla.
At low speed, mix in the flour mixture in 3 batches, alternating with the buttermilk, beginning and ending with the flour, and mixing until just combined. Fold in the chopped nectarines.
Spoon the batter into cake pan, smoothing top. Scatter the crumble evenly across the top.
Bake until cake is golden and a tester inserted into center comes out clean, 25 to 30 minutes. Cool in pan 10 minutes, then turn out onto a rack and cool 10 to 15 minutes more. Invert onto a plate and serve warm or at room temperature.