In a large bowl, with a mixer on high speed, beat egg whites with cream of tartar until thick and foamy. Gradually add sugar and continue to beat until mixture holds stiff, shiny peaks.
With a spatula, gently stir in almond extract and chopped chocolate. Spoon 1/2-tablespoon portions into 1-inch-wide mounds (or with a pastry bag fitted with a 1/2-inch plain or star tip, pipe 1-inch-wide mounds) about 1 inch apart onto cooking parchment - lined 12- by 15-inch baking sheets.
Bake meringues in a 275° regular or convection oven until dry and firm to touch on the outside and almost dry inside (break one open to test), 30 to 35 minutes; if baking two sheets at once in one oven, switch their positions halfway through baking. Let cool for 5 minutes on sheets, then slide a spatula underneath meringues and transfer to racks to cool completely.
Nutritional analysis per meringue.