200ml whole milk
4 Limes (zest finely grated, to get 2½ tbsp, then juiced, to get 3½ tbsp)
1 tsp salt
1 tsp baking powder
½ tsp bicarbonate of soda
350g caster sugar, plus 2 tbsp extra for sprinkling
100g Basil leaves, roughly chopped
3 large eggs
225ml good-quality olive oil, plus extra for greasing
For the glaze
100g icing sugar
½ tsp good-quality olive oil
3 basil leaves, roughly chopped, plus a few whole leaves for decorating
Heat the oven to 180C (160C fan)/375F/gas 5. Grease a 24cm bundt tin. In a jug, whisk the milk, ricotta and two tablespoons of lime juice. Sift the flour, salt, baking powder and bicarb into a medium bowl.
Put the caster sugar, chopped basil leaves and two tablespoons of lime zest into the bowl of a food processor and blitz until the basil is finely chopped. In a free-standing mixer with the whisk attachment in place, beat the eggs and basil leaf sugar on high speed until thick, pale and creamy – about three minutes. Turn the speed down to medium-low and drizzle in the oil in a slow, steady stream, until fully incorporated and homogeneous – about a minute. Replace the whisk with the paddle attachment and, with the speed on medium-low, add the flour and milk mixtures in three increments, starting and ending with the flour. Combine until just incorporated, taking care not to over-mix.
Pour the batter into the bundt tin, smooth the top with the back of a spoon and sprinkle over the last two tablespoons of sugar. Bake for 45-50 minutes, or until golden brown and a knife comes out clean. Leave to cool in the tin for 10 minutes, then turn out on to a rack to cool completely.
For the glaze, put the icing sugar and basil leaves into the bowl of a food processor and blitz until the leaves are very finely chopped. Add the oil and remaining tablespoon and a half of lime juice, and blitz again until smooth. Use a spoon to drizzle the glaze all over the cake, letting some of it run down the sides. Sprinkle with the remaining teaspoon and a half of zest and top with a few basil leaves.