Banana Streusel Coffee Cake

1.	Preheat oven to 350°F. Grease and flour a 9-inch springform pan.
2.	Stir together the flour, ¾ cup brown sugar, sugar, and salt in a large bowl. Blend in ¾ cup (1 ½ stick) cold butter with your fingers or pastry blender until the mixture resembles coarse meal and the butter is the size of peas.
3.	Transfer ¾ cup of the mixture to a medium bowl and blend in cinnamon, remaining ¼ cup butter, and remaining ¼ cup brown sugar until crumbly. Stir in pecans. Refrigerate steusel until ready to use.
4.	Whisk together the banana puree, egg, yolk, vanilla, baking soda and orange zest in a bowl. Stir into the remaining flour mixture and mix until just combined (batter will be stiff).
5.	Pour the batter into the prepared springform pan and sprinkle with the streusel topping. Bake until cake is golden brown and a toothpick inserted into the center comes out clean, about 1 hour to 1 ¼ hour. Cool in the pan for 30 minutes, then remove springform sides and cool completely.

	2 ½ cups all-purpose flour
	1 cup packed light or dark brown sugar
	¾ cup granulated sugar
	½ teaspoon salt
	1 cup unsalted butter , cold and cut into cubes
	1 teaspoon ground cinnamon
	1 cup pecans , toasted and chopped
	1 cup pureed bananas , about 3 medium bananas
	1 large egg
	1 large egg yolk
	1 teaspoon vanilla extract
	1 teaspoon baking soda
	1 ½ teaspoons orange zest