Preheat the oven to 350 degrees F.
Tear the croissants into pieces and put in a small gratin dish; I use a cast iron oval with a capacity of about 500ml/ 2 cups for this.
Put the sugar and water into a saucepan, and swirl around to help dissolve the sugar before putting the saucepan on the hob over medium to high heat. Caramelize the sugar and water mixture by letting it bubble away until it all turns a deep amber colour; this will take 3 to 5 minutes. Keep looking but don't be too timid.
Take the pan off the heat and add the cream - ignoring all spluttering - followed by the bourbon and milk. Whisk to mix, then still whisking add the beaten eggs. Pour this quickly over the croissants and leave to steep for 10 minutes.
Place in the preheated oven for 20 minutes and prepare to swoon.