Preheat oven to 350°. Spread almonds on a cookie sheet and toast 5 minutes. Cool, then chop roughly. Toss ½ cup almonds with confectioners’ sugar, reserving remaining ¼ cup for garnish; set nuts aside.

Reduce oven to 225°. Wet a paper towel with white vinegar and wipe the bowl and whisk of a mixer. Place egg whites in bowl, add cream of tartar and salt, then whisk on medium-high speed until foamy, about 1 minute. Gradually add granulated sugar in a very slow stream while whisking, until meringue is glossy and forms stiff peaks, about 2 minutes. Gently fold in the sugared almonds with a spatula. Drop tablespoons of batter onto a cookie sheet lined with parchment paper or nonstick baking pad. Bake 1-½ hours. Turn oven off. Let meringues stand in closed oven with the light on at least 4 hours or overnight. Garnish with the remaining almonds. Store in an airtight container.