Double Apple Streusel Coffee Cake

- adapted from the excellent You Made That Dessert? by Beth Lipton

Streusel:
1/4 cup all-purpose flour
1/4 packed dark brown sugar
2 Tbsp sugar
1/2 tsp cinnamon
1/4 tsp salt
3 tbsp cold unsalted butter, cut into pieces
1/4 cup chopped pecans

Cake:
1-1/2 cups all-purpose flour
1 cup packed dark brown sugar
1 tbsp cinnamon
1 tsp baking soda
1/2 tsp salt
3/4 cup unsweetened applesauce, at room temperature
8 Tbsp (1 stick) unsalted butter, melted and cooled slightly
1/4 cup plain yogurt, at room temperature (full fat is best, but low-fat is OK)
1 tsp vanilla extract
1 large egg, at room temperature
1 small sweet apple, such as Gala or Yellow Delicious, peeled and roughly chopped

1- Preheat oven to 350 deg. F with a rack in the center. Spray an 8-inch square pan with cooking spray.

2- For the streusel, in a medium bowl combine the flour, sugars, cinnamon, and salt. Stir to combine well. Add the butter pieces and work in with a pastry blender, two knives, or your fingers until it resembles coarse sand. Add the pecans and toss with your fingers to mix. Cover and place in the refrigerator.

3- For the cake, in a large bowl combine the flour, brown sugar, cinnamon, baking soda, and salt; whisk well to combine. Make sure all brown sugar lumps are broken up.

4- In another large bowl combine the applesauce, melted butter, yogurt, vanilla, and egg; beat with a whisk to combine well.

5- Add the flour mixture to the applesauce mixture all at once. Use a flexible spatula to stir the two mixtures together. Add the chopped apple. Scrape the bottom of the bowl to be sure there are no pockets of dry flour. Be careful not to overstir, though, as that results in a tough cake.

6- Scrape the batter into the prepared pan and spread it evenly. Sprinkle the streusel over the top.

7- Bake the cake for 50 to 55 minutes, or until a toothpick inserted in the center of the cake comes out clean. Let the cake cool in the pan on a wire rack for at least 20 minutes. Cut into pieces and serve.

(Note: I baked my cake for 15 minutes longer than the time stated. Rely on the toothpick to figure out when it's done.)