Preheat oven to 350 F. Grease a 9x9 inch baking dish or use non-stick cooking spray.
In a small mixing bowl, combine the ingredients for the crumb topping - except for the slivered almonds, using the back of a fork or a pastry cutter. Set aside.
In the bowl of a stand mixer fitted with a paddle attachment, or a large mixing bowl, cream the butter and sugars.
To the large bowl, add the egg, vanilla, and apple cider. Mix until creamy.
In a small mixing bowl, whisk together the dry ingredients.
Beat the dry ingredients into the wet ingredients.
Gently fold in the apples by hand.
Use a rubber spatula to spread the batter into the prepared baking dish.
Sprinkle the crumb topping over the cake batter. Then sprinkle the slivered almonds on top of the crumb topping.
Bake for 25-30 minutes or until toothpick inserted in the center comes out clean.