Make the apple sauce first, or use a good shop-bought one. Core and dice the apples small, about ¼ inch (5 mm) — leave the skin on if they're thin-skinned, it gives the sauce a pink blush. Put them in a saucepan with the sugar and water over medium heat and cook for 10–15 minutes, stirring now and then, until the fruit softens and most of the liquid has steamed off. You want it thick, not smooth. Cool it completely before it goes near the batter.

Peel the apples for the cake if the skins are thick — thin-skinned apples can keep theirs. Halve, core and slice them, then toss the slices in a bowl with the lemon juice so they stay pale.

Beat the butter and sugar until pale and fluffy. Add the eggs one at a time, beating well after each one.

Whisk together the flour, baking powder, vanilla sugar and cardamom. Add it to the butter mixture a little at a time on low speed, just until combined.

Press the apple slices into the batter in an even pattern, standing them up slightly so they show once the cake rises.

Mix the sugar and cinnamon and sprinkle it over the top, then scatter over the almonds.

Bake on the lowest rack at 375°F (190°C) for about 50 minutes, until a skewer comes out clean in the centre. In a deeper 9×5-inch pan, give it 55–60 minutes and tent it with foil if the almonds colour too fast. Cool on a wire rack before slicing.