For the crumb: In a mixing bowl, whisk together flour, sugar, salt, cinnamon, and nutmeg. Add the melted butter and vanilla extracts and stir with a spatula until the mixture is evenly moist. Use your fingers to pinch the mixture into crumbs of varying sizes.

In a bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside. In the bowl of an electric mixer, cream together the butter and sugar until light and fluffy. Add the eggs one at a time, beating well after each addition. Beat in the vanilla and sour cream. Add the flour mixture to the bowl, beating on low speed until the ingredients are just combined. The batter will be very thick.

Spread half the batter into a thin layer at the bottom of the pan. If the batter is difficult to spread, wet your hands and use them to spread the batter. Sprinkle the apple chunks evenly over the batter, then top with half of the crumbs. Place dollops of the remaining batter over the crumbs, again using wet hands to spread it as best you can. It’s ok if it’s thin or there are a few bare spots. Top with the remaining crumbs.

If the top is getting too brown at the 30-minute mark, cover with foil for the last 10-15 minutes. While the coffee cake bakes, whisk together the powdered sugar, cider, butter, and salt until it’s thick but pourable. Serve the cake warm with the cider drizzle.