Combine all ingredients except for bread in a medium bowl and blend with an immersion blender till completely smooth.;
Spray a casserole dish (I used an 8-inch square glass baking dish and did two layers of bread, you can use whatever you have at your disposal, you may need more or less bread and custard in that case depending on the size) and set aside.;
Dip the bread in the custard leaving it for a few seconds on each side so it soaks up the custard.;
Place in prepared casserole dish and repeat with the remaining pieces of bread.;
Pour whatever remains of the custard over the arranged slices, cover dish with plastic wrao and let chill overnight.;
When ready to bake, remove from fridge and preheat oven to 350F.;
Remove plastic wrap and replace with foil. Bake for 25 minutes then remove foil and bake for another 12 to 15 minutes. ;
In the meantime, make the syrup: whisk together maple syrup and liqueur till combined.;
When done, remove from oven let sit for 5 minutes.;
Dust with powdered sugar and serve with syrup.;
Enjoy!