Gluten-free blood orange loaf cake

For the cake
150g unsalted butter
200g caster sugar
250g ground almonds
60g polenta
3 large eggs
½ tsp table salt
1 ½ tsp baking powder

For the candied zest
80g caster sugar
4 blood oranges, pared with a zester to give thin strips

For the syrup
60g sugar
140g blood orange juice

To make the cake, cream the butter and sugar until pale and fluffy, then stir in the remaining cake ingredients. Pour the mix into a 2lb/900g loaf tin lined with greaseproof paper brushed with a little melted butter. Bake at 180C (160C fan)/gas 4 for 50 minutes, until golden brown.