In a medium sized pot, add in the champagne, water, sugar and vanilla bean and heat on medium-high heat until almost boiling, stirring occasionally.
Turn the heat down to low, and add in the pears. Simmer for 30 minutes. Remove the pears using a slotted spoon and set aside.
Continue to simmer the champagne syrup for another hour, until it reduces to about 2 cups. Make the crepes as the champagne syrup is simmering.
To make the crepes
Mix everything together in a blender, or add all the ingredients into a medium bowl and blend with a stick blender. Allow to rest 15 minutes.
Heat a cast-iron crepe pan on medium to medium-high heat (I switched between setting 5/10 and 6/10 on my stove). Make sure you give enough time for the pan to evenly heat through (about 5-7 minutes). If the pan is not hot enough, the crepes may start to stick to it.
Add about 1/2 tablespoon of oil to the crepe pan and give it a quick wipe using a paper towel. Repeat this process to add on more oil as needed while you are cooking the crepes.
Once the oil is hot, add 1/3 cup of crepe batter, and quickly spread it around the pan evenly using a crepe rake. You can also try to quickly tilt the pan to swirl it, but I find it easier to use the crepe rake to make even sized crepes. The crepes should be very thin.
Let each crepe cook for about 1 minute, then flip over and cook for an additional 30 seconds.
Remove the crepe and place on a cooling rack. The crepe will cool quickly, so if you are short on space, you can begin to stack them up after a few minutes of cooling.
Repeat with remaining batter.
To assemble the crepes
Slice the pears into 1/2 inch (1cm) thick slices and remove the core.
Place several slices of pears on the middle of a crepe. Slowly fold the two sides of the crepe over the pears, creating a triangle. Repeat with remaining crepes.
Before serving, add on two scoops of vanilla ice cream on top of each crepe and drizzle with the reduced champagne syrup.