In a medium sized bowl, mix together cornmeal, flour, salt, baking powder, egg, milk, and butter. Whisk together until smooth batter forms. Stir in corn and cayenne pepper.
Heat about a tablespoon of oil in a medium sized frying pan. Once oil is hot, scoop about 1 tablespoon sized dollops of batter on to pan, leaving about an inch between each (you will have to do several batches). Cook blinis for about 2-3 minutes per side, until golden brown. Flip and cook on other side for an additional 2 minutes. Transfer to plate and repeat until all batter is used, adding more oil inbetween batches if needed.
Combine mango, red onion, red bell pepper, and lime juice in a medium sized bowl. Stir well and add salt and pepper to taste.
Once blinis have cooled to room temperature, dollop a tablespoon or less of salsa on each and top with a little sour cream and cilantro.