Separate 1 egg white into a clean, dry bowl.
Whip the egg white with KitchenAid mixer on medium speed, about speed 6, until stiff peaks form, roughly 4 minutes.
In a saucepan, mash 2 cups fresh blueberries, mix with 1/2 cup raw honey, and heat to 270°F, checking with a candy thermometer, about 12 minutes on medium heat.
Stir in 1/8 tsp arrowroot powder into the blueberry mixture until thickened, about 1 minute, keeping the temperature at 270°F.
Slowly pour the warm blueberry mixture, heated to 270°F, into the whipped egg white while mixing on low speed, taking about 2 minutes to combine fully.
Fold in 1/8 tsp Himalayan pink salt and 1 tsp organic vanilla extract with a spatula until evenly blended, about 3 minutes.
Pour the mixture into an 11-inch by 8-inch mold with 12 cavities, each 1.25 inches by 5.5 inches by 1/4 inch deep, lined with parchment paper, and smooth the top with an offset spatula.
Refrigerate the mold for 1 hour until the nougat sets very firmly. Ninth: Remove nougat from the mold, cut into 12 bars if needed, ensuring each is 1.25 inches by 5.5 inches by 1/4 inch thick.
Optional test: Remove one nougat bar from the mold after 1 hour and gently pull it apart with your fingers; it should stretch slightly and feel dense, like saltwater taffy, with a firm, chewy bite.