Preheat your oven to 375 degrees F and spray an 8x8 inch baking dish with a non-stick spray. Line the dish with parchment paper, and spray it again with non-stick spray. Set aside.
In a medium-sized skillet, add the 1/2 cup of butter. Cook over medium-low heat, stirring occasionally, until brown bits begin to form on the bottom of the pan, and a nutty aroma fills the air. This should take approximately 7-8 minutes. Be careful, as the butter can quickly go from brown to burnt in seconds. Remove from heat and set aside.
In the bowl of your stand mixer, with paddle attachment fixed, cream together the brown butter and brown sugar until smooth and creamy. Add the egg and beat again to incorporate. Add the vanilla extract and beat again. In a medium bowl, whisk together the flour, salt and baking soda. With the mixer speed set on low, slowly add the flour mixture to the sugar mixture. Mix until just incorporated. Do not overmix. Fold in the white chocolate chops and pour the batter into the prepared pan. Smooth out the top.
In a small bowl, combine the granulated sugar and ground cinnamon. Sprinkle the cinnamon, sugar mixture on top of the blondies in an even layer.
Bake the blondies at 375 degrees F for 20-22 minutes or until a toothpick comes out clean. Remove from heat and set aside to cool.
While your blondies are cooling, prepare your Nutella caramel. To a heavy bottomed large saucepan, add the granulated sugar, and heat over medium heat. Constantly stir the mixture with a spatula. Eventually, the sugar will turn a golden amber color, forming clumps. Once the sugar has completely melted, add the butter and continue to stir. The mixture will bubble, but watch as the mixture is subject to burn. Continue to stir until the butter has melted. Very, very slowly drizzle the heavy cream into the sugar and butter mixture. It will bubble and this is ok. This happens when you add a cold product to something as hot as the sugar mixture. Boil for 1 minute, then remove from heat. Immediately, whisk in the Nutella, vanilla extract and salt. Set aside to cool for a couple of minutes.
Once the caramel has cooled, pour on top of the blondies, smoothing out the top with an offset spatula. Set aside.
In a small bowl, whisk together the confectioner's sugar, milk, vanilla extract and salt for the glaze. Once smooth and creamy, drizzle on top of the blondies. Cover and place in the refrigerator for 15-20 minutes before you cut into bars.
The snickerdoodle blondies will store in an airtight container for about a week. Enjoy!