How to Make It
Prepare the Cookies: Preheat oven to 350°F. Spread almond flour in an even layer on a parchment paper-lined baking sheet. Bake in preheated oven until lightly toasted, about 10 minutes.
Beat butter, almond paste, and vanilla with an electric mixer on medium-low speed until well combined, about 4 minutes. Add powdered sugar; beat on low speed until well combined, about 2 minutes.
Whisk together all-purpose flour, toasted almond flour, and salt in a bowl. Add flour mixture to butter mixture; beat on low speed until just combined. Turn dough out onto a work surface; knead until dough comes together, 4 to 5 times. Divide dough in half. Shape each half into a 6-inch disk, and wrap each disk in plastic wrap. Chill 1 hour.
Preheat oven to 350°F. Let 1 dough disk stand at room temperature 10 minutes. Unwrap dough disk, and roll to 1/4-inch thickness on a lightly floured surface. Cut with a 3 1/2-inch star-shaped cookie cutter, rerolling scraps once. Place cookies 2 inches apart on parchment paper-lined baking sheets.
Bake in preheated oven until edges are golden brown, 9 to 10 minutes, switching pans top rack to bottom rack halfway through baking. Cool on pans 2 minutes. Remove cookies to wire racks, and cool completely, about 20 minutes. Repeat process with remaining dough disk.
Prepare the Icing: Beat powdered sugar, meringue powder, and 6 teaspoons of the water on medium speed until well combined, 3 to 4 minutes. Add up to 1 teaspoon water, 1/4 teaspoon at a time, and beat until desired consistency is reached. Spread icing over cookies, and top with toasted almonds.