Are you doing to make a caramel or “dulce de leche”? In the UK and probably in the US you can buy nestle carnation caramel, where they’ve already boiled the condensed milk for you. So it really cuts on cooking time.
You can make banoffee pie similarly by mixing 100g melted butter, with 250g digestive biscuits ground to a sand like texture. Then pressi the mixture into the bottom or a loose bottomed cake tin, and cover with the caramel, layer with chopped bananas and cover with whipped cream. Sprinkle with grated chocolate before serving.