Cinnamon Toast Crunch Cupcakes

Josh requested these as the small group dessert the week of his birthday. They are to die for -- seriously, the frosting is amazing.

CUPCAKE: (Modified from Once Upon My Life)
3 cups all-purpose flour
2 cups sugar
1 tablespoon baking powder
2 teaspoons cinnamon
1/2 teaspoon nutmeg
3/4 teaspoon salt
1 cup unsalted butter, cut into 1-inch cubes, at room temperature
4 large eggs
1 cup whole milk
1 teaspoon pure vanilla extract

1. Preheat oven to 350 degrees. Line cupcake pans with paper liners; set aside.
2. Combine flour, sugar, baking powder, cinnamon, nutmeg and salt; mix on low speed until combined. Add butter, mixing until just coated with flour.
3. Whisk together eggs, milk, and vanilla.
4. With mixer on medium speed, add wet ingredients in 3 parts, scraping down sides of bowl before each addition; beat until ingredients are incorporated but do not overbeat.
5. Place three tablespoons of batter in each prepared baking cup.
6. Bake 20-25 minutes.
7. Transfer to a wire rack to cool completely.

FROSTING: (borrowed from Mele Cotte)
5 cups powdered sugar
1 ½ tsp ground cinnamon
1 cup unsalted butter, room temperature
1 tsp. vanilla
~ ¼ cup cream or milk

1. Whisk together powdered sugar and cinnamon; set aside.
2. Mix butter until fluffy and pale. Add vanilla and mix until combined. Reduce speed on low and gradually add cinnamon sugar one cup at a time alternating with a tablespoon of milk. (The amount of milk needed may vary.) Beat until smooth.