Preheat the oven to 180C/350F/Gas mark 4
Mix the flour, oatmeal and baking powder together. Rub in the butter until the mixture resembles breadcrumbs. Stir in the sugar and add enough milk to make a soft dough. Knead lightly.
Roll out on a lightly-floured board to a thickness of about ¼ inch (5mm). Using a 3 inch (7.5cm) plain round biscuit cutter stamp out the biscuits. Prick all over with a fork and transfer them to a greased baking tray. Bake for 15-20 minutes, until light brown. Transfer to a wire rack to cool.
When cold, melt the carob, stir in the milk. Using a tablespoon, spread the top of the biscuits with the melted carob. Just before it sets make patterns in the carob with a fork. Allow the carob to cool completely before storing the biscuits in an airtight tin.
