Dolcetti di Marzapane (Italian Marzipan Cookies)

Combine ground almonds, 2 1/2 cups sugar, eggs, lemon zest, and vanilla extract in a bowl; mix into a smooth dough.

Preheat oven to 400 degrees F (200 degrees C). Line a baking sheet with parchment paper.

Pour 1/4 cup sugar onto a shallow plate. Roll dough into walnut-size balls and roll in sugar. Place 2 inches apart on the baking sheet.

Bake in the preheated oven until lightly browned, 10 to 15 minutes. Remove from oven and transfer carefully to a wire rack. Cool completely before serving.