In a small bowl, mix melted butter, flour, light brown sugar, cinnamon, and salt until large crumbs form.
1/2 cup unsalted butter, 1 1/4 cups all-purpose flour, 6 tablespoons light brown sugar, 2 teaspoons ground cinnamon, 1/4 teaspoon salt
Distribute the crumbs evenly over the apples.
Bake for one hour or until a toothpick inserted into the center of the cake comes out clean.
Set on the counter to cool.
Glaze Instructions
Mix powdered sugar and apple cider until you have a thick but still runny glaze. Add more apple cider if needed to get the perfect consistency that slowly drips off of a spoon.
1/2 cup powdered sugar, 1 1/2 teaspoons apple cider
Drizzle over cooled cake.
Video
Notes
You can substitute yogurt (plain or Greek) for the sour cream if that's what you have on hand. Don't substitute with milk or other liquids.The cake is best eaten within 2 days. You can store it in the refrigerator and eat it for up to a week, but the crumbs will absorb too much moisture from the apple layer after 2 days and will get kind of mushy.