Ingredients

Step by step

1. Preheat the oven to 200°C, fan 180°C, gas 6, and grease and line a loose-based 20cm round cake tin with baking paper. Whisk the egg whites until stiff using an electric whisk. Also whisk together the egg yolks and sugar in a separate large bowl – the mixture should not be too pale and thick – then gently fold the whisked whites into the mixture, a third at a time. Fold in the ground almonds, the baking powder and ground cinnamon, mixing until thoroughly and evenly incorporated.
2. Spoon the cake mixture into the tin, then give it a couple of taps on a work surface to bring up any large air bubbles. Bake for 25-30 minutes until the top feels springy to the touch and the sides are starting to shrink away from the tin. A skewer inserted into the centre should come out clean. Run a knife around the edge of the cake, remove it, and leave to cool on a wire rack.
3. For the jam, hull the strawberries and slice from stem to tip. Put in a medium nonstick saucepan with the agave syrup, gently heat until the syrup starts to sizzle, then cover the pan and cook for about 4 minutes until the fruit releases its juices, gently shaking the pan halfway through. Tip the fruit into a sieve set over a medium bowl and leave to drain for a few minutes. Return the syrup to the pan and simmer until the consistency of a thin, sticky jam, adding any more juices given out by the fruit as it drains. Stir in the vanilla and lemon juice to taste, and pour over the fruit in a bowl. Cover with clingfilm, leave to cool, then chill until required.
4. Dust the cake with a little icing sugar. Mix the yogurt with the soured cream or crème fraîche. Serve the cake in slices with the jammy strawberries spooned over, and a dollop of the yogurt mixture.