1) Preheat the oven to 350°F. Grease one or two baking sheets, or line with parchment paper.
2) Whisk together the egg whites, sugar, and salt until foamy.
3) Whisk in the maple syrup, butter, and flavors until incorporated.
4) Add the flour and whisk until smooth.
5) To use a maple leaf cookie stencil: Place the stencil on one of the baking sheets. Spread an even layer of batter into each of the individual leaf patterns; you'll need about 1 teaspoon per leaf, more or less (the less batter, the crisper the cookies).
6) Remove the stencil, and bake the cookies for 7 to 9 minutes.
7) To shape the finished cookies: Have a rolling pin at your side. As soon as the cookies come out of the oven, drape them over the rolling pin, and allow them to cool until set, about 1 minute. Remove the curled cookies from the pin, and cool completely on a rack.
8) To leave cookies flat, simply transfer the hot cookies on parchment directly to a cooling rack.
Yield: 35 to 50 cookies, depending on size.