Preheat oven to 325°F.

Line the bottom of an 8” round baking pan with parchment paper. (Tip: I recommend a pan with a removable bottom. I use a springform pan when I bake upside down cakes.)

Spray parchment and sides of the pan with nonstick baking spray; set pan aside. (Tip: Spray parchment paper generously so that the apples don’t stick!)

Using an electric mixer, add sugar, eggs and vanilla extract. Beat on medium speed for 3-4 minutes, or until mixture is light yellow in color.

Add flour, baking powder and salt; mix on low speed until just combined.

Using a separate bowl, add melted butter, buttermilk and vegetable oil; stir until well combined.

Add liquid mixture to the larger bowl and mix on low speed until just combined. (Tip: Make sure to scrape the bottom and sides of the bowl to ensure mixture is well combined!)

Using a medium bowl, combine all of the topping ingredients (melted butter, brown sugar, cinnamon, allspice, ginger, salt and apples). Spread this mixture evenly into bottom of the prepared baking pan.

Pour batter over the apples.

Bake for 30 minutes and then cover top of the pan with aluminum foil. Continue baking for 25-30 more minutes, or until a toothpick inserted into the center of the cake comes out mostly clean. (Tip: If using a pan with a removable bottom, put a sheet pan on the oven rack underneath to catch any potential drips.)

Let cake cool in pan for 5 minutes.

Run a table knife around edge of the cake and then place a serving plate upside-down on top of the pan. Invert the cake onto the serving plate. (Note: If the parchment paper comes out with the cake, simply peel it off the top and discard.)

Let cake cool for 25-30 minutes before slicing and serving.