Combine the rapeseed oil, cider vinegar and oat milk in a jug. Heat the oven to 180C/160C fan/gas 4. Line a 12-hole cupcake or muffin tray with paper cases. Tip the flour, baking powder and sugar into a large bowl. Make a well in the middle and slowly pour in the wet mixture, whisking constantly. Add the vanilla paste and stir to combine. Divide evenly between the paper cases and bake for 15-20 mins until golden and a skewer inserted into the middle of a cupcake comes out clean. Transfer to a cooling rack to cool completely.

For the icing, beat the plant block and vanilla until soft and creamy, around 2 mins. Add the icing sugar in batches, beating well after each addition, and a large pinch of salt. Transfer to a piping bag fitted with a star nozzle. Pipe swirls on top of each cooled cupcake. Will keep, iced, for up to three days in an airtight container.