NY style crumb cake
From the cookbook Baked: Explorations
as seen on vanillasugarblog.com

Crumb topping
1 cup dark brown sugar
1/2 cup sugar
1 1/2 tablespoons ground cinnamon
1/2 teaspoon salt
1 cup unsalted butter, melted, and warm
2 1/2 cups all purpose flour

2 1/2 cups all purpose flour
1 ts baking soda
¾ ts baking powder
½ ts salt
12 TB unsalted butter, room temperature
1 ½ cups sugar
2 large eggs
1 ¼ cups sour cream
1 ts pure vanilla extract

Preheat the oven to 350 degrees F and position the rack in the center. Butter the sides and bottom of a glass 9 x 13-inch pan. You can use a metal pan, but the edges of the cake may turn crispy (although that is not traditional, it is not an altogether bad thing).

Make the crumb topping
In a medium bowl, stir together both sugars, the salt and cinnamon. Add the melted butter and whisk until combined. Fold in the flour until it is absorbed and set the mixture aside.

Prepare the Cake
Sift flour, baking soda, baking powder, and salt into medium bowl and set aside.

Using electric mixer, beat room-temperature butter in large bowl until smooth. Add sugar and beat until light and fluffy; add eggs 1 at a time, beating until well blended after each addition. Add sour cream and vanilla extract and beat just until blended. Add flour mixture in 3 parts, beating just until incorporated after each addition.

Assemble the cake
Pour the batter into the prepared baking pan, spread batter evenly. Use your hands to scoop up a handful of the topping and make a fist. The topping should hold together. Break off in chunks and drop them over cake. Repeat to use all the topping. Remember the topping with look very thick.

Bake the cake for 45 to 55 minutes or until tester inserted into center comes out clean. Rotate the pan two times during the baking process. Cool entire pan on wire rack for about 30 minutes before devouring.

The cake will last 3 days, tightly covered, at room temperature.