Heat a frying pan over a medium heat and dry-fry the nuts until golden. Remove and set aside.
Melt the butter in a medium saucepan, add the rice and cook, stirring, for 1 minute.
Stir 4 teaspoons of the sugar and the cinnamon into the hot milk, then start adding the milk to the rice, adding a little more once each addition has been absorbed. This should take about 20 minutes, when the rice should be soft but still with a little bite.
Spoon the risotto into serving bowls.
Blitz the nuts in a food processor with the remaining teaspoon of sugar, then sprinkle the mix over the top of risotto. Serve immediately.