Preheat the oven to 350 F/ 180 C/ gas mark 4 (or 170 C/gas 3 fan). Line a muffin pan with 12 paper cupcake cases.
Place all the cupcake ingredients in a large bowl and using an electric mixer beat on low until all the ingredients have been incorporated and the mixture is smooth. Spoon the batter into the cupcake cases and bake for 20 minutes.
Remove from the oven, set aside for 10 minutes, then place on a cooling rack.
To make the icing combine the icing ingredients and stir together thoroughly until the mixture is smooth. Once cooled completely decorate the cupcakes.
Ensure your oven temperature is not too high. If you are using a regular oven bake these cupcakes in the centre at 180 C/ gas mark 4. For fan assisted ovens the temperature should be a little lower - 170 C/ gas mark 3. The right temperature will produce perfect, evenly risen cupcakes without high peaks.
Use readymade pumpkin spice (2.5 tsp) instead of individual spices in the recipe if you prefer.
Ensure your butter is quite soft (for both the cupcakes and the frosting) so it's easy to mix in with the other ingredients.
Do NOT overmix the batter.
Store the cupcakes, once completely cooled, in an airtight container for up to 3 days.
Keep the frosting covered, refrigerated and decorate the cupcakes just before serving.
Freeze the cupcakes (without the frosting) for up to 3 months.