Preheat oven to 400.
Spray a 6 count donut pan with non-stick cooking spray, set aside.
In medium bowl mix together your flour, cereal, baking powder, sugar and salt and whisk together until combined.
Add in your egg, sour cream, milk, butter and vanilla and mix until combined.
Transfer to a piping bag and pipe evenly into wells of donut pan.
Bake for about 10 minutes or until golden and donuts pop back when touched.
Remove from oven and place on cooling rack to cool.
Meanwhile in bowl mix together our powdered sugar, milk and vanilla until smoothe.
Once donuts are cool dip tops of donuts into glaze and place onto cooling rack and let sit for a few minutes then dip again.
Top with Cinnamon Toast Crunch and enjoy!