Christoph's upside-down apple almond cake
Units
Temperature
Servings
Ingredients
Base
- 40 g sliced almonds, almond spears or flaked almonds also work rounded
- 70 g light brown sugar rounded
- 450 g apples, about 3 large, unpeeled, cored, sliced paper-thin rounded
- 15 ml fresh lemon juice rounded
- 3 g ground cinnamon rounded
- 1 g ground nutmeg rounded
- 10 g cornstarch, for tossing the apples rounded
Almond batter
- 240 g fine blanched almond flour, not coarse almond meal rounded
- 30 g cornstarch rounded
- 10 g gluten-free baking powder rounded
- 6 g ground cinnamon rounded
- 1 g ground nutmeg rounded
- 2 g fine salt rounded
- 4 large eggs, separated rounded
- 100 g light brown sugar rounded
- 90 g plain Greek yogurt rounded
- 60 ml neutral oil rounded
- 15 ml fresh lemon juice rounded
- 5 ml vanilla extract rounded
Method
Method
- Heat the oven to 175°C. Butter a 20 cm round cake tin generously, including up the sides, then line the base with a parchment round and butter the parchment too. The pan needs to release cleanly later, so do not skimp on this step.
- Scatter the sliced almonds evenly over the base of the tin. Scatter the brown sugar evenly over the almonds.
- Toss the apple slices with the lemon juice, cinnamon, nutmeg, and cornstarch until evenly coated. Arrange them over the almonds and sugar in a fairly even layer, overlapping as needed to fill gaps.
- Whisk the almond flour, cornstarch, baking powder, cinnamon, nutmeg, and salt in a medium bowl. Separate the eggs between two clean bowls. Whisk the yolks with the brown sugar until pale and slightly thickened, about 1 minute, then whisk in the yogurt, oil, lemon juice, and vanilla until smooth. Stir in the dry ingredients; the batter will be thick.
- Beat the egg whites to firm, glossy peaks. Stir one-quarter of the whites into the thick batter to loosen it, then gently fold in the rest in two additions.
- Pour the batter evenly over the apple layer and spread it to the edges of the tin, covering the fruit completely.
- Bake for 60 to 75 minutes. Check at the 35 to 40 minute mark: if the top is browning quickly, cover loosely with foil for the rest of the bake. The cake is done when the top springs back when pressed and a skewer through the centre comes out with a few damp crumbs, no wet batter. This takes noticeably longer than a normal almond-flour cake, because the fruit and sugar base insulates the centre from the tin.
- Cool in the tin for 15 minutes only, no longer. While the sugar layer is still warm and loose, run a thin knife around the edge, set a plate over the tin, and invert the two together in one confident motion. Lift the tin away; if any almonds or apple stick to the base, lift them out and press them back into place.
- Let cool for at least 20 to 25 minutes before slicing, so the caramelized top sets slightly.
Notes
- Cool in the tin briefly, not fully. If the cake sits too long before flipping, the caramelized sugar layer can set hard and stick to the tin instead of releasing cleanly.
- Use a firm, tart baking apple that holds its shape, such as Elstar, Boskoop, or Granny Smith. A soft eating apple like Golden Delicious will collapse into the base.
- Gluten-free when the almond flour, cornstarch, baking powder, and vanilla are all verified gluten-free.
- Refrigerate covered for up to 4 days. Bring slices toward room temperature before serving, or freeze individual slices for up to 2 months.
Ingredient substitutions
- Almond spears, flaked almonds, or roughly chopped whole almonds all work for the base; what matters is an even layer, not the exact shape.