Prep: Preheat your oven to 350° F. Place a piece of parchment paper across the bottom of a 9-inch springform pan and then secure the sides. Spray the inside of the pan with nonstick spray.
Make the Apple Filling & Topping: Add all the apple filling ingredients except the corn starch & water to a medium/large saucepan. Cook over medium high heat, stirring for about 8-10 minutes – or until the apples are tender and the mixture has caramelized. Stir together cornstarch and water in a small bowl until dissolved, and stir into the apples over medium high heat. Cook for 1 minute or so until the juices thicken up. Remove from heat and set aside.
4 large honeycrisp apples, peeled and diced, 1/3 cup dark brown sugar , 2 tbsp salted butter, 1 and 3/4 tsp cinnamon, 1/2 tsp nutmeg, 1/4 tsp allspice, 1/4 tsp clovces, 1 tbsp boiled apple cider, 1 tsp corn starch, 1 tsp water
Make the Cake Batter: Melt the butter in a large mixing bowl. Whisk in the vegetable oil, then the sugars, and then the eggs. Whisk in the sour cream and vanilla. Add the dry ingredients to the wet, and gently fold in with a spatula until halfway combined, then pour in the milk and continue folding everything together until just combined.
1/3 cup salted butter, melted, 1/4 cup vegetable oil, 1/2 cup granulated sugar , 1/3 cup + 1 tbsp light brown sugar, packed, 2 large eggs, at room temperature , 1/3 cup full fat sour cream, at room temperature , 1 1/2 tsp vanilla extract , 1 and 3/4 cups all-purpose flour, spooned & leveled, 2 tsp baking powder, 1/4 tsp baking soda, 1/4 tsp salt, 1 and 1/4 tsp cinnamon, 1/2 cup milk, 1/2 tsp nutmeg
Assemble the Cake: Spread half the batter in your prepared pan. Add half the apples in an even layer. Spread on the remaining batter, and repeat with the remaining apples.
Bake: Bake the cake for 46 to 52 minutes. A toothpick inserted into the center should have moist crumbs - not wet batter. Make the glaze here (see step below). Let the cake cool in the pan for 15-20 minutes, then release the sides and drizzle on the glaze. Place the cake on a cooling rack to cool for 30-40 more minutes before slicing and serving.
Make the Glaze: Whisk together all glaze ingredients until smooth.
3/4 cup powdered sugar , 1 tbsp water, if needed to thin the glaze, 1/2 tsp vanilla extract , 2-3 tbsp boiled apple cider
Serve + Store: Release the sides of the springform pan and let cake cool about 20-30 minutes before pouring the glaze on. Slice and enjoy! Allow leftovers to cool to room temperature and store in an airtight container in the fridge for 2-3 days. (It can stay at room temperature if you left off the glaze.)