For the cake
300g self raising flour (or ⅔ SR and ⅓ sponge flour)
1½ tsp baking powder
300g soft margarine (I used Stork)
125g Half Spoon sugar alternative*
5 medium eggs
zest and juice of 1 lemon
a splash of milk if needed
For the topping
180g cream cheese
25g softened butter
2 heaped tblsp icing sugar
A handful of blueberries
Grease and line the base of a 22 or 23 cm square tin. Preheat the oven to 190°C / 170° fan / gas mk 5.
Put all the cake ingredients except for the blueberries into a large bowl and beat well until combined. Beat in a splash (about a tablespoon) of milk if the mixture seems quite stiff (mine was but I now wonder if adding the milk is why the blueberries sank. I might omit it and go with a stiffer mixture next time). Fold in the blueberries until evenly distributed.
Spoon the mixture into the tin and level the top. Tap the tin on the worktop a few times to settle the mixture and dispel any air bubbles.
Bake for 25-35 minutes until done. Cool in the tin for a few minutes then turn out onto a wire rack.
To make the topping, beat the cream cheese and butter together until smooth. Sift in the icing sugar and beat in. When the cake is completely cool, spread the topping over and swirl it or use a fork to create a pattern. Distribute the extra blueberries over the top. Dust with icing sugar before serving.
Cuts into 12-16 portions.
*If you want to make the recipe with caster sugar instead of Half Spoon, follow the advice in the link. Essentially it implies that you would use twice as much sugar and less baking powder. I haven't tried it!