Preheat oven to 350 degrees F. Spray a baking sheet with a light coating of non-stick spray or line with a sheet of parchment paper.
In a medium bowl, whisk the baking soda, salt, and flour. Set aside.
In a large bowl, using a hand electric mixer or in the bowl of a stand mixer fitted with a paddle attachment, cream together the butter and granulated sugar until smooth and creamy.
Add the brown sugar, egg, and vanilla; mix until combined.
Add the flour mixture into the wet and mix until a dough has formed.
Place the cinnamon toast crunch cereal in a bag and crush into pieces. Fold the cereal into the cookie dough.
Using a medium cookie scoop, scoop balls of cookie dough and place on the prepared cookie sheet 2 inches apart.
Bake for 9-10 minutes, just until the edges are crisped up and the center no longer looks wet.
Allow to cool on the sheet for a few minutes and then move to a wire cooling rack to finish cooling. Once cooled, prepare the glaze.