Grease a round baking tin with butter and dust with some flour.
Heat sufficient water in a steamer.
Cream together butter and castor sugar in a bowl till light and fluffy. Add eggs and cream further. Add vanilla essence and blend well.
Sift refined flour, baking powder and baking soda into the bowl and fold lightly. Add semolina and fold lightly till well blended.
Grate a lemon into it to get the zest and mix well. Add milk and blend well into a smooth batter.
Pour the batter in the prepared tin, level it out and tap the tin. Put the tin in the steamer, cover and steam for 20-25 minutes or till fully done.
Slice remaining lemon and remove seeds. Place the slices onto a hot non-stick pan. Add granulated sugar and let it caramelize. Switch off heat and transfer the caramelized lemon slices on a plate.
To make lemon syrup, heat granulated sugar and lemon juice in a non-stick pan. Mix well till the sugar dissolves and the syrup thickens.
Demould the cake onto a serving plate. Drizzle lemon syrup on top, garnish with caramelized lemon slices and serve immediately.