Preheat oven to 350°F. Spread almonds on a baking sheet or pie plate and bake, stirring occasionally, until lightly toasted, 5 to 10 minutes. Let cool.
Reduce the oven temperature to 200°F. Line 2 large baking sheets with parchment paper.
Pulse the toasted almonds with 1/3 cup of the sugar in a food processor until finely chopped. Add cocoa, cornstarch and cinnamon and pulse just until mixed.eat egg whites in a large bowl with an electric mixer on low speed just until frothy. Add cream of tartar, increase the mixer speed to medium and beat until soft peaks form. Gradually add the remaining 2/3 cup sugar, 2 tablespoons at a time, beating until the whites form firm but still moist peaks. Add vanilla and almond extracts and beat just until blended. Gently fold the cocoa mixture into the beaten whites in 2 additions, just until blended. (A few streaks of white may remain.)
Drop heaping teaspoonfuls of the batter, 1 inch apart, onto the prepared baking sheets, or pipe the batter through a pastry bag fitted with a 1/2-inch plain tip. Bake, using both oven racks, for 1 1/2 hours, alternating the position of the pans halfway through the baking time. Turn off the oven and let the meringues cool in the oven for 1 hour, then peel them off the parchment paper.
Melt chocolate in a small bowl set over a pan of almost simmering water or in the microwave. Use a small pastry brush to apply a thin coating of chocolate onto the flat side of the meringues. Let the meringues stand, chocolate-side up, until the chocolate has set.