Grease a large bowl with the butter; set aside. In a large heavy saucepan over medium heat, combine the sugar, cornstarch and honey. Cook and stir until sugar is dissolved and mixture comes to a boil. Cover and boil for 1 minute. Uncover; cook, without stirring, until a candy thermometer reads 286° (soft-crack stage).
In a stand mixer, beat egg whites until stiff peaks form. With mixer running on high speed, carefully pour hot sugar mixture in a slow, steady stream into the mixing bowl. Beat on high for 10 minutes or until mixture holds its shape and is lukewarm, scraping sides of bowl occasionally.
Fold in ground almonds and cinnamon. Transfer to prepared bowl; cool to room temperature. Shape into 1-in. balls; roll balls in chopped almonds. Store in an airtight container.