Picture by Jonathan Pollock

Serves: 12 slices
Prep time: 10 minutes

When I did Cook Yourself Thin I made a virtually fat free lemon cake. The idea was that by boiling the lemons you create a really flavoursome sticky pureé that binds the cake, meaning no need for butter! Yes, the almonds and the egg yolks have fat in them but I assure you, it has far less calories than a regular cake. Bakewell tart in its gooey berry glory translates brilliantly into cake form and using seasonal blackberries instead of raspberries makes a refreshing change.

1 orange
3 medium free-range eggs
200g fructose, xylitol or golden caster sugar (fructose and Xylitol are natural and have a really low GI level)
55g plain flour
200g ground almonds
1 teaspoon baking powder
300g fresh blackberries
1 handful flaked almonds

Put the orange in a saucepan, cover with water and bring to the boil. Reduce the heat and simmer for 1 hour. Halve the orange, remove the pips, then purée in a blender, skin and all.

Preheat the oven to 170°C/gas 3. Oil a 20cm, round spring-form cake tin and line with baking parchment.

Beat the eggs and sugar together until pale and thick. Fold in the flour, baking powder, almonds and orange purée. Finally stir in the fresh blackberries

Pour into the tin, sprinkle with the flaked almonds and bake for one hour until the top is golden. Do keep an eye on it for the last 15 minutes as fructose sugar is slightly more likely to catch. The cake will be fairly dark though. Leave to cool for 10 minutes, then turn out on to a rack and cool completely. Sift over icing sugar and serve with a cup of tea.