Pick the mulberries then cut out the stems. Set aside.
Zest 2 limes and set the zest aside. Cut the limes in half then juice them. Set the juice aside.
Line the base & sides of the cake tin with baking paper & butter the paper.
Preheat the oven to 180C (355F) or 160C for a fan-forced oven.
Cream the butter and sugar together until paler & well blended.
Crack the eggs together into a separate bowl and whisk lightly.
Gradually beat the eggs into the butter & sugar mixture. Add a little of the flour towards the end to prevent curdling.
Beat in the lime zest.
Using a spatula, gently fold in the flour, then the almond meal.
Fold in enough lime juice to give a suitable consistency. You don't need to use it all if you don't want to, and you can use the leftover in the drizzle.
Fold in 3/4 of the mulberries, then turn the batter into the prepared tin.
Smooth the surface then place the remaining mulberries randomly across the top.
Bake for one hour or until a skewer comes out clean. If the surface starts to brown too much, cover with foil during cooking.
Meanwhile, make the syrup. Put the lime juice, zest & sugar in a small non-stick saucepan over a gentle heat. Stir intermittently. The sugar should dissolve fully without the mixture coming to a boil.
As soon as the cake comes out of the oven, prick it all over with a skewer then spoon the syrup over it. Leave to cool in the tin.
When the cake has completely cooled, turn it out of the tin, remove the paper & serve.