Preheat the oven to 350 and prepare an 8x8-inch pan with parchment paper. Set to the side.
In a large bowl, whisk together the brown sugar, egg, vanilla, and salt. Add in the cooled butter and mix until the batter is light brown in color.
Fold in the flour and cornstarch. The dough is combined when it is streak-free of the dry ingredients.
Mix in the chocolate chips using a rubber spatula, making sure they are distributed evenly.
Add the blondie dough to the pan using a rubber spatula. Top the blondies with any extra chocolate chips.
Bake in the oven for 30-35 minutes. Let the blondies cool in the pan.