Tip: While this cake has a streusel topping, it also goes very well with Vanilla Nutmeg Ice Cream
Preheat an oven to 325 F degrees and set the rack in the lower third of the oven. Butter a 9" x 13" cake pan and set aside. Have all ingredients at room temperature.
Prepare the streusel: In a bowl, stir together the flour, pecans, brown sugar, granulated sugar, cinnamon and salt. Using a pastry blender or fork, cut in the butter until coarse crumbs form. Set aside.
In a medium bowl, whisk together the flour, cinnamon, salt, baking powder, ginger and nutmeg together. Set aside.
In the bowl of a stand mixer fitted with the flat beater, beat the butter on medium speed until creamy and smooth, about 30 seconds. Add the granulated sugar and brown sugar and continue beating until light and fluffy, about 5 minutes, stopping the mixer occasionally to scrape down the sides of the bowl. Add the eggs one at a time, beating well after each addition, then beat in the vanilla extract.
On low speed, add the flour mixture in three additions, alternating with the milk and ending with the flour. Beat each addition only until just incorporated. Stop the mixer occasionally to scrape down the sides of the bowl. Spread half the batter into the prepared pan, then layer with half the sliced apples. Top with half the streusel. Repeat with the remaining ingredients.
Bake until the top springs back when lightly touched, and the edges have pulled away from the pan sides, about 60 to 65 minutes. Set pan on a wire cake rack and let cool to room temperature before cutting into squares and serving.
Serves 12 to 16.