Preheat oven to 350°F. Line a baking sheet with parchment paper.
Pulse almonds in a food processor until finely chopped but not pasty. In a large bowl stir together nuts, flour, zest and salt.
Add sugar, cream, corn syrup and butter to a small saucepan. Over medium heat, stir occasionally, until the mixture comes to a rolling boil and sugar is completely dissolved. Continue to boil for 1 minute. Remove from heat and stir in vanilla, then pour into almond mixture. Stir just to combine. Set aside until cool enough to handle, 30 minutes.
Scoop rounded teaspoons (for 3-inch cookies) of batter and roll into balls. Place on prepared baking sheet, leaving about 3-4 inches between each cookie.
Bake 1 pan at a time, until cookies are thin and an even golden brown color throughout, rotating pans halfway through baking time, about 10-11 minutes. Cool on baking sheet for 5 minutes, then transfer to racks to cool. Repeat with remaining batter. Makes 5 dozen cookies.
Approximate Nutrient Analysis per small thin cookie:
40 calories, 2.5 g fat, 1 g saturated fat, 5 mg cholesterol, 10 mg sodium, 4 g carbohydrate, 0 g fiber, 3 g sugar, 1 g protein