Spread your choice of filling in one slice of bread and top with another. Make another set as such.
Whisk together the egg, milk, sugar, cinnamon and vanilla till well combined.
Dip each of the bread in it till well coated all over. Then roll in the crushed corn flakes.
Heat skillet and slather butter generously. Cook on low flame, flipping till both sides are golden brown.
Serve hot as is or with fruits and whipped cream.