Place two racks in the center and upper third of the oven and preheat oven to 325 degrees F. Line two baking sheets with parchment paper and set aside.
In a small bowl, mix together granulated sugar, orange zest, and scraped vanilla seeds. Use your fingers to works the zest and vanilla into the sugar, creating a fragrant, moist sugar.
Place sugar in the bowl of an electric stand mixer fitted with a paddle attachment. Add the almond paste and salt. Beat on medium speed creating a crumbly sugar and almond mixture.
While almond mixture is combining in the mixer, place two egg whites in a small bowl. Whisk with a fork until loose and frothy. This will help in pouring the egg whites into the mixer. If the eggs are unbeaten, they’ll just plop into the mixing bowl and not pour in.
With the mixer on medium speed, gradually pour the egg whites in to the crumbly almond and sugar mixture. Beat until a smooth paste is formed. Add the almond extract and beat to combine.
Spoon or scoop batter by the heaping tablespoonful onto the prepared baking sheet. Sprinkle generously with powdered sugar. Using the tips of three of your fingers, make indentations in each cookie.
Bake cookies for 20 to 25 minutes or until cookies are lightly browned on top. Remove from the oven and allow to cool on the pan. Store cookies in an airtight container at room temperature for up to 5 days.
Recipe by How to Decorate at https://www.ballarddesigns.com/howtodecorate/2015/11/holiday-cookie-recipes-vanilla-cloud/