Pre-heat your oven to 180°C/160°C fan.Line muffin tins with 12 cupcake cases.
Put the raisins (100g) into a small bowl or jug and cover with water. Leave to soak while you prepare the rest of the cake mixture.
Coarsely grate the carrot (150g).
Beat together the oil (150ml) and brown sugar (135g) until combined.
Beat in the egg (2 large) until combined.
Sift in the self-raising flour (165g), bicarbonate of soda (½ tsp), cinnamon (1 tsp) and mixed spice (⅓ tsp). Fold the dry ingredients into the egg, oil and sugar mixture until combined.
Drain the water from the raisins and add the raisins and grated carrot into the cake mixture. Fold together until combined.
Divide the mixture between the 12 cupcake cases. Bake for 20 minutes. Check the cupcakes are cooked through by inserting a skewer into the centre. If it comes out clean they are ready, if not, pop them back into the oven for a couple more minutes.
Move them to a cooling rack to cool completely.
Cream Cheese Buttercream
Cut the butter (125g) into cubes and beat (either by hand or using a mixer on a slow speed ) until soft.
Sift the icing sugar (125g) and beat it into the butter until fully combined and smooth.
Add the cream cheese (250g) and vanilla extract (¼ tsp) and beat until thoroughly combined and smooth.
Check the consistency of your buttercream. It should be firm, but soft enough to pipe. If it is too firm, then beat in a little milk (no more than a teaspoon at a time) until you have the right consistency.
Pipe your buttercream onto your cupcakes and serve.
❄️ Suitable for freezing - You can find details on how to freeze these cupcakes either decorated or undecorated just above the recipe.
If you would like to use a different style of piping on your cupcakes, then you may need a different quantity of buttercream. Take a look at the recipe notes in my original cream cheese buttercream recipe for other styles, and the amount of buttercream you'll need.