Preheat the oven to 350°F (180°C) Grease an 9” (23 cm) round pan by spraying it with baking spray (or by rubbing with butter), then place a round parchment paper sheet on the bottom of the pan. Grease the top of the parchment paper as well. Set aside.

Whisk together all of the dry ingredients in a bowl. Set aside for now.

Make the streusel topping by combining the dry ingredients, whisking them together, then, adding the chopped, cold butter. Use a pastry cutter or two forks to mix the butter into the dry ingredients until the texture resembles coarse breadcrumbs. Place into the refrigerator until needed.

Peel and core the apples. Slice thinly (about 1/4” wide). Set aside for now.

Place the room temperature butter in the bowl of a stand mixer. Using a paddle attachment, cream it for about a minute on medium speed. Add the sugar a little at a time, then continue mixing until it is light and fluffy. This will take about 4 to 5 minutes.

Add the vanilla extract and continue mixing for 30 seconds.

Add the eggs one at a time, mixing well after each addition. Add the sour cream and milk and mix well again. The mixture will look curdled. That’s okay.

Add the wet ingredients to the dry ones and fold until just combined and no dry streaks remain.

Transfer the batter to the prepared pan and spread evenly.

Top the batter with a single layer of apple slices. Don’t worry about being neat, because the slices will be covered with streusel. You may have some slices left over, and that’s okay. Have a snack! 😆

Cover the apples evenly with the streusel topping, and place in the preheated oven.

Start checking for doneness at 40 minutes. You may have to bake longer until an inserted toothpick tests clean. Remove from the oven and allow to cool completely on a metal rack.

Place a dish over the top of the cake, then invert the cake and remove the pan and parchment paper. Place another dish on the now exposed bottom of the cake and flip the cake over again so it is now right side up.

Store the cake covered and at room temperature for up to a day. After this, refrigerate it. It is best served at room temp temperature or warmed. You can warm it by heating it briefly in a toaster oven or microwave.

Notes: 🍎 Any good baking apple can work in this recipe. For this particular cake, I used Honeycrisp apples. You can also use Granny Smith apples for a tarter flavor. 🍏 If you like, you can sprinkle the cake with powdered sugar before serving it!