Place eggs in a beater and begin to beat. Beat until the eggs just begin to form stiff peaks.
SLOWLY, pour in the maple as the mixer continues to mix.
Then slowly add extract if using.
When the egg whites are thick and form stiff peaks, transfer to a pastry bag or ziplock back with the tip cut off and press the egg whites out onto parchment lined cookie sheets. Keep them small (just slightly larger than a hershey's kiss) or they won't bake properly.
Bake at 200 F., venting the oven door with a wooden spoon handle, for 2-3 hours. They will be light brown from the maple, that's okay. If there is any doubt, break one open to see if the middle is cooked. It should not be wet in the middle, or sticky on the outside.
Allow to cool fully before removing from parchment.
Video
Notes
Please note that the nutrition data is a ballpark figure. Exact data is not possible.