Bake for about 15 minutes, then flip the nuts, retossing them in the maple syrup mixture. Bake for another 10-15 minutes until the sugar bubbles and starts to crisp up on the nuts. Remove from oven and let cool on a wire rack for about 2 minutes, then use a spatula to break up the nuts to separate them before the sugar sets completely. Don't worry if it still looks a little wet or syrupy, as the pan cools, the sugar will harden.