In a small bowl, combine 2 teaspoons sugar, 125ml water, yeast, milk and 125g flour. Mix until well blended, then cover and allow to rise in a warm place until light and bubbly, about 30 minutes.
In a large bowl, beat the eggs, salt and 200g caster sugar until light and fluffy. Stir in the melted butter and lemon zest. Stir in the sponge, then gradually mix in the flour. Knead in the bowl for about 10 minutes, then knead in the raisins. Cover and let rise in a warm place until doubled in volume.
Punch down dough and knead for a couple of turns then let it rise again. Grease 4 small coffee tins with soft butter. Fill the prepared tins about 1/3 full and let rise until the dough is even with the rim. Preheat the oven to 200 C / Gas 6.
Bake for 15 minutes in the preheated oven, then turn down the temperature to 180 C / Gas 4. Continue baking the bread for another 40 minutes. Avoid letting the top get too brown, if it begins to brown too quickly, cover the top with foil. Remove baked loaves from the tins and cool on a wire rack.