Preheat oven to 350°F (175°C). Line a baking sheet with parchment paper and lightly dust with gluten-free flour.
In a large bowl, beat egg yolks with half the granulated sugar until pale and thick. Stir in vanilla extract.
In a separate clean and dry bowl, beat egg whites until soft peaks form. Gradually add the remaining granulated sugar and beat until stiff, glossy peaks form.
Gently fold the egg whites into the egg yolk mixture in two additions. Be careful not to overmix.
Sift the gluten-free flour over the mixture and gently fold in until just combined.
Transfer the batter to a piping bag fitted with a large round tip. Pipe 3-inch long ladyfingers onto the prepared baking sheet, leaving space between each one.
Dust the ladyfingers with powdered sugar.
Bake for 10-12 minutes, or until lightly golden brown. Let cool completely on the baking sheet before removing.
Notes
Store ladyfingers in an airtight container at room temperature for up to 3 days.