Fruit cupcakes with spiced vanilla buttercream

Cupcakes:

3/4 cup / 125gms flame raisins

½ cup / 75gms currants

220gms butter at room temperature

2 cups / 400gms sugar

4 large free-range eggs

1 tsp vanilla extract

1 tsp cinnamon

½ tsp all spice

3 cups cake flour / 360gms

2 tsp baking powder

1 cup milk

Spiced vanilla buttercream:

5.5 cups icing sugar

270gms butter

60ml /1/4 cup milk

2 tsp vanilla extract

3/4 tsp cinnamon

¼ tsp ground all spice