1.Preheat oven to moderate. 180°C (160°C fan-forced). Lightly grease or line a 12-hole, 1/3-cup muffin pan with paper patty cases.
2.In a large bowl, using an electric mixer, beat butter and sugar together until pale and fluffy. Beat in zest.
3.Add eggs, one at a time, beating well after each addition.
4.Fold almond meal into creamed mixture alternately with milk, beginning and ending with almond meal. Divide evenly among cases until 2/3 full. Bake 15-20 minutes, until cooked when tested.
5.To make syrup: Meanwhile, in a small saucepan, combine sugar, water and orange zest and juice. Stir over low heat, without boiling, until sugar dissolves. Increase heat to high and bring to boil. Reduce heat to medium and simmer, 6-8 minutes. until syrup is golden and slightly thickened. Add orange slices. Simmer 4-5 minutes, until tender. Spoon hot syrup over hot cupcakes. Top with orange slices and cool in pan.
When cakes are cool, transfer them to a wire rack to cool completely then store in an airtight container.Note