Directions:
Arrange an oven rack in the center position and preheat the oven to 180°C. Press a 30cm square of baking paper into the bottom of a 23cm springform cake tin, smoothing it up the sides and pressing down on any folds to flatten.
Set the apples on a cutting board and, working one at a time, use a sharp knife to slice off a thin piece of flesh from the base and stem ends of the apples, creating two flat surfaces on each (discard or snack on the trim). Stand each apple upright and use an apple corer to cut out the cores, then use a mandoline or a sharp knife to cut them horizontally into 3mm-thick slices (try to slice them evenly, but some variation in thickness is fine).
Arrange about one-quarter of the apple slices in the bottom of the prepared cake tin and drizzle with 1 tablespoon of the honey. Layer in more apples, drizzle with another tablespoon of honey, and repeat two more times with the remaining apples and honey. Drizzle 1 tablespoon of the olive oil over the layers of apples and honey.
Transfer to the oven and roast until the slices have released their juices and are translucent and tender (it's okay if some of them start to fall apart), 1 hour to 1 hour 15 minutes, folding the apples gently every 20 minutes with a spatula. Set the tin aside and allow the apples to cool. Leave the oven on.
In a medium bowl, whisk together the flour, baking powder, salt, baking soda, cinnamon, allspice, and nutmeg. Set aside.
In a large bowl, combine the eggs and 100 g of the demerara sugar and whisk vigorously until the mixture is slightly thickened, about 1 minute. Slowly stream in the remaining olive oil, whisking constantly, until the mixture is smooth, satiny, and thick. Whisk in the vanilla and vinegar. Add the dry ingredients and whisk just until the last trace of flour disappears and you have a smooth, evenly mixed batter.
Set aside 10 or 11 apple slices for arranging on top of the cake, then tip the rest of the apples and the roasting juices into the bowl with the batter (leave the baking paper in the tin and reserve for baking the cake). Fold the mixture with a flexible spatula, scraping the bottom and sides of the bowl, until the apples are evenly distributed and the juices have been absorbed. Don't worry if folding breaks up some of the apple slices— the softer pieces will just blend into the cake.
Scrape the batter into the reserved cake tin and smooth into an even layer. Arrange the reserved apple slices across the surface, then sprinkle with the remaining demerara sugar. Bake until the cake is deep golden brown across the surface and a toothpick or cake tester inserted into the center comes out clean, 45 to 50 minutes. Let the cake cool completely in the tin.
I await your comments! Enjoy!
