Heat oven to 375 degrees. Line a baking sheet with parchment, and lightly coat with nonstick cooking spray. In the bowl of an electric mixer, combine ground almonds, sugar, and egg whites. Beat on medium speed until thick, about 3 minutes. Beat in extracts.Advertisement
Roll dough into 1-inch balls, and place 2 inches apart on prepared baking sheet. Flatten each ball with dampened fingers, and gently press 2 sliced almonds on top.
Bake until just brown on top, about 10 minutes. Remove from oven, and place on a wire rack for 5 to 10 minutes. Remove cookies from baking sheet while still warm, and place on a wire rack to cool.