Set the rack to the lower center part of the oven and preheat to 325 degrees F.

Line a heavy duty 13×18 inch baking sheet with nonstick foil or parchment paper.

In a mixing bowl, vigorously whisk the egg whites until very foamy. Gradually whisk in the sugar, then whisk in the melted butter and vanilla until smooth. Whisk in the salt, baking powder and cinnamon, then whisk in the nonfat milk powder. Add the flour and stir until smooth.

Empty batter onto the lined cookie sheet and spread as thinly as possible using the back of a spoon or scraper.

Mix together the cinnamon and sugar and sprinkle evenly over the top. If using pecans, sprinkle them on top.

Bake in the lower center of the oven for 17- 20 minutes, checking at 17 minutes. Edges should be brown but not burnt. Remove from oven. With a pizza cutter or knife, immediately cut into pieces without separating – you want shards, similar to what you’d get if making peanut brittle.

Let cool completely. If you are left with a few thick, chewy, pieces, return them to the oven and bake at 250 for 20 minutes, then re-cool. If your batter is thin enough the first time, you should not need the second bake.