Preheat the oven to 350 degrees and prepare a baking sheet with parchment.
Melt butter and set aside to cool.
In a medium bowl, whisk together dry ingredients. Set aside.
In a stand mixer set with a paddle attachment, combine cooled butter and sugar. Mix until combined.
Add egg, egg yolk and vanilla extract. Mix until combined.
Add dry ingredients. Mix until just combined.
Using a small cookie scoop, scoop out dough (about 1 tablespoon) and place on the baking sheet.
Arrange about 6 cookie dough balls to one baking sheet.
Place in the oven for 10 minutes.
Pull baking sheet out of the oven and add about 1 tablespoon of Cinnamon Toast Crunch cereal to the middle of each cookie. Press the cereal lightly into the cookie.
Place back in the oven and cook for another 2-3 minutes.
Take out baking sheet and leave cookies on the sheet to cool.
Once they are cooled, drizzle a little white chocolate over each cookie.