Preheat the oven to 180C/350F and line a cupcake tray with 12 cases.
Place oil, sugar, eggs and vanilla into a large bowl, or the bowl of your stand mixer, and mix on medium-high speed until smooth, slightly frothy and well combined.
Place flour, salt, baking powder, bicarb, cinnamon and ginger into a medium sized bowl an stir briefly to combine. Tip into the bowl with the oil mixture.
Add the shredded carrot to the bowl with the flour/oil mix and then mix on low-medium speed until everything is well combined and smooth.
Divide the batter between the cupcake liners, each one should be 3/4 full.
Place in the oven for 18-22 minutes until risen, golden and an inserted skewer into the centre comes out clean.
Transfer to a wire rack to cool completely as soon as possible to ensure the liners don't sit in the cupcake tray and then peel away from the cakes.
Once cool, make the frosting: place marshmallow fluff and butter into a large bowl/the bowl of your stand mixer and beat on high speed until light and fluffy, 2-3 minutes.
Add in the icing sugar and vanilla extract, scraping down the sides as necessary and mix on low until the mixture starts to come together. Once the mixture starts to combine, turn the speed up to medium-high and mix until everything is combined. At this stage, add milk if required to give you a frosting which is pipeable and continue to mix on medium-high until you have light, fluffy frosting with no lumps!
You can either spoon on the frosting, or I prefer to fill a piping bag fitted with a plain, 1/2 inch nozzle and then pipe rounds into the centre of each cupcake. With a plain nozzle, I start in the centre and just wiggle the nozzle around in circles, with constant pressure until the cupcake is covered. If I was using a star nozzle, I'd start to pipe around the edge of each cupcake before continue into the centre.
You can also use carrot decorations for garnish, if desired.
Carrot Cupcakes will keep in an airtight container at room temperature for 4 days, or in the fridge for 5 days.