Preheat the oven to 350 degrees Fahrenheit and coat a Bundt pan with nonstick cooking spray.

Pour 1/4 cup of the melted butter into the pan, tilting the pan to distribute it evenly. Sprinkle the brown sugar evenly over the butter. Top with the nuts.

In a large bowl, beat the eggs. Add the granulated sugar, sour cream, applesauce, remaining 1/4 cup butter, salt, and cinnamon and whisk to combine. Add the noodles and thoroughly mix to coat. Pour into the prepared Bundt pan on top of the walnut mixture.

Bake for one hour, or until browned. Remove from the oven and let cool for five minutes. Run a knife around the edges or gently shake the kugel to loosen, then invert the pan onto a serving plate. Remove the pan; the nuts will be on top of the kugel.