In New York City where I live, blueberry season is fairly long, since we have blueberries from the south, then New Jersey, then finally from Maine and Michigan, consecutively throughout several months. I love this type of cake and blueberries are the perfect fruit for it—they melt to a jamlike consistency between the cake batter and crumb topping while the cake is baking.

Makes one 9 x 13 x 2-inch cake, about 24 squares

Crumb Topping

2 cups all-purpose flour (spoon flour into dry-measure cup and level off)

1 teaspoon baking powder

1/3 cup sugar

1/3 cup light brown sugar, firmly packed

1/2 teaspoon ground cinnamon

1/4 teaspoon freshly grated nutmeg

12 tablespoons (1 1/2 sticks) unsalted butter, melted

Cake Batter

16 tablespoons (2 sticks) unsalted butter, softened

1 1/2 cups sugar

3 large eggs

2 teaspoons vanilla extract

2 1/2 cups all-purpose flour (spoon flour into dry-measure cup and level off)

2 teaspoons baking powder

3 egg yolks

1/4 cup milk or buttermilk

4 cups (two 1-pint baskets) blueberries, rinsed, picked over, and patted dry

One 9 x 13 x 2-inch pan, buttered and lined fully (bottom and sides) with parchment or foil

Set a rack in the middle level of the oven and preheat to 350˚F.
For the crumb topping, mix the flour, baking powder, sugars, cinnamon, and nutmeg in a bowl. Stir in the melted butter. Rub the mixture between your fingers to form coarse crumbs. Set aside.
In a large mixer bowl, beat the butter and sugar until soft and light. Add the eggs one at a time, beating smooth after each addition. Beat in the vanilla.
Stir together the flour and baking powder and add to the batter in three additions, alternating with the yolks and milk, beginning and ending with the flour. Spread the batter evenly in the prepared pan.
Scatter the blueberries evenly over the batter, pressing them in gently. Repeat with the crumb mixture.
Bake the cake until batter is firm and crumbs are well colored, about 40 minutes. Cool the cake in the pan on a rack. Cut the cooled cake into squares. Remove the squares from the pan to a platter.

Serving: This a great breakfast cake and also transports well, right in the pan, to a picnic.

Storage: Wrap the cooled cake in plastic wrap and keep it at room temperature. Freeze for longer storage. Defrost cake and bring it to room temperature before serving.

Variations

Sour Cherry Crumb Cake: Substitute 3 cups pitted sour cherries for the blueberries.

Plum Crumb Cake: Substitute 2 pounds Italian prune plums, pitted and quartered, for the blueberries. Place the plum quarters on the batter, cut side down, forming neat rows.