Preheat the oven to 180°C (Gas mark 4/350°F). Line a 12 hole muffin tin with 12 cupcake cases.
Place the butter in a mixing bowl and whisk together with the caster sugar until light and fluffy. Break the eggs into a bowl and lightly whisk with a fork. Add the eggs a little at a time to the butter and sugar mix, whisking in between.
Sift the flour on top, and using an electric whisk on a low speed, gently blend the ingredients together. Add the milk and vanilla extract and blend again. Increase the mixer speed and whisk for a few more seconds until well mixed.
Divide the cake mixture between the cupcake cases and smooth over the tops. Bake for 20-25 minutes until risen, golden and springy to the touch.
Once the cakes are cooked, transfer to a wire rack to cool completely.
Whilst the cakes finish cooling, make the buttercream icing. Whisk the butter with an electric whisk until light and fluffy. Sift in the icing sugar, a little at a time, until completely combined. Add the vanilla extract and whisk again.
Once the cupcakes are completely cool, spread a generous layer of buttercream icing over the top of each one.
Pour the desiccated coconut onto a small bowl, then dip each cupcake, icing side down, into the coconut to coat.
Make the lamb faces – ‘glue’ 2 candy eyes to each giant chocolate button using the writing icing.
Cut each smaller chocolate button in half for the ears - these will be assembled with the ear pieces behind the giant chocolate button face.
Spread a little leftover buttercream on the back of a giant chocolate button. Press it into the top of a cupcake for the head, then push a chocolate ‘ear’ into the buttercream on each side to finish.
Repeat with the remaining cupcakes to turn them all into lambs.