Preheat the oven to 120°C (250°F/Gas 1).
Place 2 cups of the corn kernels and the onion, eggs, coriander, flour, baking powder, salt and pepper in a food processor and process until combined.
Place in a large bowl, add the remaining corn and stir to combine.
Heat 1 tablespoon of the vegetable oil in a non-stick frying pan over a medium to high heat.
When the oil is hot, drop 2 heaped tablespoons of mixture per sweetcorn cake into the pan and cook in batches of three for 1 minute each side.
Drain on paper towels and keep warm in the oven while you are making the rest of the cakes. Serve with the avocado salsa.
Place all the ingredients in a bowl and stir very gently to combine.