Preheat the oven to 350 degrees F. Spray the donut pan with nonstick cooking spray. Set aside.
Place 1 cup of the crushed cinnamon toast crunch and the buttermilk in a large mixing bowl. Give a slight stir and set aside.
Combine the flour, cinnamon, baking soda, and baking powder in a medium mixing bowl and mix.
Lightly whisk the egg before adding it to the bowl with the cereal and buttermilk in it. Add the oil, maple syrup, vanilla, Greek yogurt, brown sugar and melted butter to the bowl as well. Stir until thoroughly mixed.
Add the flour mixture to the buttermilk mixture, a bit at a time, and stir it in until thoroughly combined.
Grab your prepared donut pan and fill each cavity about ¾ of the way full. Use a piping bag or a spoon.
Bake for 10 minutes or until the tops of the donuts spring back when lightly pressed.
Do not remove the donuts from the pan. Cool on a wire rack for about 10 minutes.
While the donuts are cooling, mix together all the ingredients for the glaze, except the cereal, and stir until thoroughly combined.
Gently remove the donuts from the pan and dip the tops of the donuts in the prepared glaze, before placing them glaze up on a piece of parchment paper or a wire rack.
Crush some of the remaining cinnamon toast crunch, while leaving some of the pieces still whole. Place a couple whole pieces of cereal on each donut, in a diagonal manner, then sprinkle with crushed cereal.
Enjoy!
Notes
Immediately after glazing donuts, sprinkle with crushed cereal. If you allow the glaze to harden, the cereal will not stick.When making the glaze, add the milk one tablespoon at a time until you get the right consistency. If you don't have a donut pan, try this recipe to make mini muffins or regular size muffins instead. Adjust baking time based on the size of your muffin pan.