Plum coffee cake

Ingredients

1 cup sugar
1 cup ground walnuts, pecans or almonds
1 teaspoon ground cinnamon
1 teaspoon ground nutmeg
3 tablespoons unsalted butter, at room temperature
1 1/2 cups all-purpose flour
2 teaspoons baking powder
1/2 teaspoon kosher salt
1 egg
2/3 cup buttermilk
1/4 cup unsalted butter, melted and cooled
5 ripe plums, cut into 1/4-inch slices

Directions

Preheat oven to 350 degrees. Butter and flour an 8-by-8-inch baking dish. In a small bowl, combine 1/4 cup of the sugar, the ground nuts, cinnamon and nutmeg. With your fingers, add the softened butter and work it into the mixture with your fingers until it resembles a coarse crumble.

In another small bowl, combine the flour, baking powder and salt. In a separate bowl, combine the egg and remaining 3/4 cup sugar and blend with an electric mixer on medium speed until smooth. Pour in the buttermilk and mix thoroughly. Add the flour mixture, blend until just smooth, and then slowly add the melted butter. Blend until well mixed, 2 to 3 minutes. Pour batter into the prepared baking dish. Gently arrange the plum slices on top of the batter in rows.

Sprinkle the nut mixture evenly over the plums. Bake for 30 minutes, until a toothpick inserted into the center comes out clean. Remove from the oven and allow to cool for 10 minutes. Cut into squares and serve warm or at room temperature.