Grease and parchment line (with overhangs) an 8x8 inch baking pan. Grease the tops and sides of the parchment, as well.
After preparing your pan, grind up your freeze dried mangoes into a powder and measure out ½ cup of the mango powder.
In a stand mixer fitted with the whisk attachment, add the gelatin, ¼ cup cold water, and ground mango's and mix on low for a few seconds then let stand.
In a medium saucepan, add the other ¼ cup water, sugar, light corn syrup, and salt and turn to medium heat. Whisk a few times until the sugar dissolves, then allow the mixture to bubble and come to 240 degrees F. You’ll need to use a candy thermometer.
When the sugar reaches 240 degrees F, turn the mixer on to low speed and drizzle in all of the hot sugar very slowly (will take 1-2 minutes). Raise the mixture to high speed and whip for 10-12 minutes. In the last minute, add in the vanilla. If you’d like, at this point, you can also add a bit of food coloring to enhance the orange color.
Pour the marshmallow (scraping down the sides) into the greased and parchment lined pan and spread evenly. Allow to sit at room temperature for 24 hours, very lightly covered (not actually touching the marshmallow) just to protect the top from any debris.