Preheat a griddle on medium heat. Slice each croissant in half lengthwise. Place cut side up in a large flat sheet pan. Crack eggs into a blender, and add an equal amount of milk, and the almond extract. Blend for about 30 seconds, until eggs are thoroughly blended. Pour mixture over the croissants and let soak in completely, turning after a few minutes.
Butter the griddle, and place croissants cut-side down on the hot griddle, and cook for a few minutes, until puffed up and browned, turn and cook for two more minutes. Serve with a few sliced almonds sprinkled over it, and dust with powdered sugar.