How to make
Crepe batter: In a bowl, beat the eggs, sugar, vanilla, salt with a whisk. Beat by hand until it foams up well. Add the milk and flour. Beat thoroughly so there's no lumps.
Add the melted warm butter (but not hot), stir and pour in the carbonated water. Beat until the batter becomes smooth.
Melt a small lump of butter in a pan and smear it along the bottom and sides with a silicone brush. Pour on a medium-sized ladle of batter. Once it's ready on one side, flip it over to the other for 1 more min.
Take it out and smear the actual crepe with the silicone brush (with plenty of butter). For each new ladle of crepe butter, place a new lump of butter and smear it along the bottom of the pan. Repeat this process for the rest of the mixture. Fold the prepared crepes into quarters.
Orange sauce: Squeeze out about 3-4 large oranges + 1 lemon. Combine them.
Put a pot with a thick bottom on a medium stove to heat up. Pour in 1/3 of the sugar, leave it to melt and lighten up, add another 1/3 sugar. Leave it to melt and finally add the remaining sugar.
Leave it to caramelize to a red-golden color. Add in the orange/lemon juices. The caramel will harden but once you remove it from the stove and stir a bit it will begin to melt.
Next, add the cubes of butter and leave to simmer on a moderate heat for about 10-15 min. to reduce.
Pour half a medium ladle of the orange-lemon sauce into a large pan and arrange the quarters of crepes on top, overlapping them carefully in the thicker side.
Pour on all of the sauce on top and leave to simmer for about 5 min. to warm up again. Pour on the liqueur and flambe using a lighter to boil off the alcohol and leave just its aroma.
Serve right away, sprinkled with grated orange rind.
Source: HomeCooking
Note: I didn't have oranges at the time so I used about 8 large mandarins.