Saffron cake with nut toffee topping

1 packet saffron
210 g Dansukker Granulated Sugar
200 g butter
2 eggs
3 g Dansukker Vanilla Sugar
150 ml milk
240 g plain flour 
10 g baking powder

Nut toffee topping
60 g pistachios
30 g pecan nuts
30 g almonds
100 g butter
50 ml whipping cream
95 g Dansukker Light Muscovado Sugar
70 g Dansukker Light Syrup

Set the oven to 175°C using top and bottom heat.

Crush the saffron in a mortar with 1 tbsp sugar. Melt the butter and stir in the saffron sugar. Beat the eggs, the remaining sugar and the vanilla sugar until fluffy. Stir in the butter mixture and the milk.

Mix the flour with the baking powder and fold into the batter.

Grease a spring-form tin, about 23 cm in diameter, and line the sides with strips of parchment paper. Pour the mixture into the tin and bake at the centre of the oven for about 30-35 minutes.

Make the nut toffee topping immediately, so that it has time to stand and thicken. Coarsely chop the nuts and set aside. Melt the butter and stir in the cream, muscovado sugar and syrup. Boil the mixture until it turns golden brown and thickens slightly, stirring frequently. Stir in the nuts.

Remove the cake from the oven. Move the rack higher up and set the temperature to 200°C, on the grill setting. Spread the nut toffee topping over the cake and bake at the centre of the oven for about 10 minutes. Check that the topping doesn't burn. It should be golden brown.