In a shallow bowl, beat the egg and mix through the double cream, vanilla and sugar.
Cut the croissant in half widthways and place in the french toast mix to cover. Turn over so the top is covered as well. Let the excess drip off and then cover in crunchy cornflakes. This can be done in a shallow bowl.
Place a frying pan on a medium heat with a knob of butter and then turn and do the outside.
Fry the bacon until crisp and fill in the croissant. Top with a drizzle of maple syrup.
