Step 1: Prepare your pan
Preheat your oven to 350 degrees. Line a 9 x 13 inch baking dish with parchment paper, leaving a slight overhang to make lifting the bars easier later.

Step 2: Brown the butter
Place the butter in a medium saucepan over medium heat. Allow it to melt completely. Continue cooking, swirling the pan occasionally, until it turns golden brown and releases a nutty aroma. Watch carefully as it can brown quickly. Remove from heat and let it cool for about 20 minutes.

Step 3: Combine the sugars
Transfer the cooled brown butter to a large mixing bowl. Add the brown sugar and granulated sugar, stirring until smooth and well blended.

Step 4: Add eggs and vanilla
Mix in the eggs and vanilla extract until fully incorporated and creamy.

Step 5: Mix in dry ingredients
Gradually stir in the flour, ground cinnamon, baking soda, and salt. Mix just until combined. Mixing the dough too much can result in dense bars rather than a soft and chewy texture. Gently fold in the cinnamon chips.

Step 6: Press and top
Spread the dough evenly into the prepared baking dish, pressing it into an even layer. In a small bowl, combine the remaining granulated sugar and ground cinnamon. Scatter the mixture evenly across the surface of the dough.

Step 7: Bake
Bake for 25 to 30 minutes, until the center is fully set and a toothpick inserted in the middle comes out with just a few moist crumbs.

Step 8: Cool and slice
Let the bars cool in the pan for about 30 minutes. Lift them out using the parchment paper and cut into squares with a plastic knife for clean slices.