Place the cornflakes in a plastic bag. Crush them with your hands or bash them with a rolling pin, then tip on to a plate and set aside.
Put the butter and sugar into a mixing bowl and cream them together with a wooden spoon until pale and fluffy. Add the egg yolk and vanilla essence and stir in. Sift in the flour and cornflour and stir them into the mix.
Take walnut-sized amounts of the mixture and make them into about 14 balls. Roll the balls in the crushed cornflakes until covered, then place them on a baking sheet lined with nonstick baking paper, leaving plenty of space between them, and decorate the top of each one with half a glacé cherry.
Bake the biscuits in a preheated oven, 190°C (375°F), Gas Mark 5, for 15 minutes, or until a light golden brown, then remove from the oven and allow to cool a little before transferring to a wire cooling rack.