With toasted almond flour, ample sour cherries and buttermilk for moisture and tenderness, this oil-based cake is best eaten on the day after it's baked - simply wrap it tightly in plastic after it's cooled and keep it on the counter.
Preheat oven to 180°C/350°F. Brush a 9in (23cm) springform pan with oil and cover the bottom with a round of parchment, smoothing out any bubbles. Set aside.
Add the almond flour to a large skillet and set over medium heat. Toast the flour, stirring frequently to prevent burning, until begins to take on colour and smells fragrant - about 5 minutes. Add to a medium mixing bowl.
Add the plain flour, baking powder, baking soda and salt to the bowl with the almond flour. Whisk to combine and set aside.
Add the sugar and orange zest to a large mixing bowl. Use your fingertips to rub the zest into the sugar, releasing its oils, until the sugar resembles wet sand.
Add the eggs and buttermilk to the sugar. Whisk vigorously until light, pale and frothy - about one minute. Whisking constantly, slowly stream in the oil until well combined and emulsified.
Pour the dry ingredients into the wet ingredients and whisk until just combined, Whisk in the orange blossom water (or vanilla). Using a large flexible spatula, fold in ¾ of the sour cherries.
Scrape the batter into the prepared pan and top with the remaining cherries. Sprinkle with demerara sugar.
Bake for 35-45 minutes or until puffed, golden and a skewer inserted into the middle of the cake comes out clean. Allow to cool completely in the pan before unmoulding.