For the pancake batter: Put the flour and salt in a bowl and make a well in the center. Crack the eggs into the well, then pour in about a little of the milk and half of the butter. Start whisking from the center, gradually drawing the flour into the eggs, milk and melted butter. Once all the flour has been incorporated, beat until you have a thick smooth paste, then gradually beat in the rest of the milk.
For the caramel sauce: Put the butter and golden syrup into a small saucepan and bring to the boil. Reduce the heat and allow the mixture to simmer and bubble for about 3 minutes, until the sauce thickens. Remove from the heat.
For the banana filling: Coat the bananas in the sugar. Melt the butter in a large nonstick frying pan over medium heat. Add the bananas and cook on both sides until golden. Transfer to a plate and add a squeeze of lime juice.
Cook the pancakes: Wipe out the frying pan, place over medium-high heat and smear with a little of the remaining melted butter. Add a ladleful of the batter and swirl the pan until the batter completely coats the base.
Cook the pancake for 1 to 2 minutes on one side, then flip over and turn the heat down to low. Top with two pieces of caramelized banana and drizzle 1 tablespoon of the condensed milk over each one. Sprinkle some of the coconut flakes on top and wrap up into a parcel to enclose the filling. Flip over and cook for another couple of minutes, turning every 30 seconds or so. Transfer to a plate and keep warm while you cook the remaining pancakes.
Put each pancake parcel on a warmed plate and cut into small squares, then drizzle over a little of the caramel sauce and scatter over the toasted sesame seeds. The remainder of the caramel sauce can be served separately.