Preheat the oven to 350ºF. Line a couple of baking sheets with parchment paper.
In the bowl of a food processor, combine the almonds with the flour, sugar, cornstarch, and salt. Process until finely ground and well mixed. Add the butter and vanilla, then pulse the mixture for 30 seconds. Process everything to form a dough.
Form tablespoons of dough into round balls and place on cookie sheet, 1 inch apart. Bake until golden brown on bottom for about 16 minutes or so. Let cookies cool completely on sheet because they are very delicate when warm.
Melt the dark chocolate in a bowl in the microwave on power level 5 for 30 second increments. When the chocolate is melted, dip the base of each cookie in chocolate and place on parchment to set.