I pinned this recipe a while ago. The original recipe called for jam, but I decided that I didn't want to use it. Until I read a review that said it was better with jam. So I went with the blueberry jam that it called for. The reviewer said any jam would work, so I have a long list of flavors I'd like to try now (next up: raspberry). But frankly, the blueberry is so good, that I may not ever stray from it.
New York Style Crumb Cake
From no other than Ms. Martha Stewart
For the crumb topping:
3 1/2 cups cake flour (not self-rising)
2/3 cup granulated sugar
2/3 cup packed dark-brown sugar
1 1/2 teaspoons ground cinnamon
2 1/2 sticks unsalted butter, melted
For the cake:
1 1/2 sticks unsalted butter, room temperature, plus more for pan
2 1/2 cups cake flour (not self-rising)
1/2 teaspoon baking soda
1 cup granulated sugar
2 large eggs plus 2 large egg yolks
1 teaspoon pure vanilla extract
2/3 cup low-fat buttermilk
1 cup store-bought blueberry jam (optional)
Confectioners' sugar, for dusting
Make the crumb topping:
Mix together flour, sugars, cinnamon, and 1/2 teaspoon salt in a medium bowl.
Pour warm melted butter over mixture, and mix using your hands until medium to large clumps form.
Preheat oven to 325 degrees.
Make the cake:
Butter (I used Pam) a 9-by-13-inch baking pan.
Whisk together flour, baking soda, and 1/2 teaspoon salt in a medium bowl.
Beat butter and granulated sugar with a mixer on medium speed until pale and fluffy, about 2 minutes.
Beat in eggs and yolks, 1 at a time, then vanilla.
Beat in flour mixture in 3 additions, alternating with buttermilk, beginning and ending with flour. Continue to beat until well combined.
Spoon batter into pan, and spread evenly using an offset spatula.
Spread with jam, if using.
Sprinkle crumb-topping mixture evenly over top.
Bake until golden brown and a toothpick inserted into the center comes out clean, about 1 hour.
Transfer pan to a wire rack.
Let cake cool slightly, about 15 minutes.
Dust with confectioners' sugar.
Serve warm or at room temperature.