Method
1. Prepare a clean springform pan
2. Pre-heat oven - 160°C
3. Heat unsalted butter in a clean saucepan until lightly browned then set aside
4. Mix in vanilla extract to the saucepan
5. Grind hazelnuts, then set aside in the bowl
6. Add powdered sugar and gluten-free flour to the bowl with nuts and mix
7. Add egg white and granulated sugar to a clean stand mixer bowl
8. Whisk until soft peaks form then set aside
9. Transfer butter to nuts
10. Transfer egg whites to nuts
11. Pour the batter into prepared pan
12. Bake until skewer tests clean - 45 min, 160°C
13. Let cool completely
14. Dust with powdered sugar