Buttercake can be made up to two days ahead. Store in an airtight container. Ice and decorate on the day of serving.
150g unsalted butter, chopped, at room temperature
3⁄4 cup caster sugar
3 tsps finely grated orange rind
2 eggs, at room temperature
1⁄2 cup milk
1 1/3 cups self-raising our Edible owers, to decorate (optional)
1 cup icing sugar mixture
3-4 tsps of orange juice
Grease a 20cm-round cake pan. Line base and side with baking paper, extending paper 2cm above pan edge.
2 Beat butter, sugar and rind in a small bowl of an electric mixer until light and fluffy. Beat in eggs, one at a time, until combined. Transfer to a large bowl.
3 Add milk and sifted our in two batches, stirring until combined. Spoon into prepared pan. Smooth over top.
4 Cook in a moderately slow oven (160C) for about 40 minutes, or until a skewer inserted into centre comes out clean. Remove from oven. Stand in pan for 10 minutes. Turn out onto a wire rack to cool.
5 To make icing, combine sugar and juice in a bowl. Stir until smooth.
6 Spoon icing over cake. Decorate with edible owers.