In a small bowl, let the Cinnamon Toast Crunch cereal steep in the milk for about 30 minutes. Then strain out the cereal milk and set aside.
Cupcakes
Preheat the oven to 350°F and line a 12 cup pan with cupcake liners.
Whisk the cake flour, baking powder, cinnamon, and salt together in a large bowl.
In a separate bowl, whisk together the melted brown butter, granulated sugar, brown sugar until combined.
Then add in the eggs and vanilla and whisk until fully combined and smooth.
Stir in about half of the flour mixture. Then stir in ½ cup of the cereal milk and the rest of the flour mixture and mix until fully combined.
Pour about ¼ cup of batter into each cupcake liner (they should be about halfway full).
Bake at 350°F for 18-22 minutes or until a cake tester comes out clean.
Remove from cupcake pan and let cool on wire rack. Let cupcakes cool completely before frosting.
While the cupcakes are still warm, lightly brush the tops of the cupcakes with a little bit of the leftover cereal milk.
Let the cupcakes cool completely before frosting.
Buttercream
In a large bowl using a handheld or stand mixer fitted with a paddle attachment, cream the softened brown butter until smooth.
Add in the powdered sugar ¼ cup at a time until fully combined and smooth. Then mix in the vanilla and cinnamon.
Slowly drizzle in the cereal milk until fully incorporated. Beat on high for 3-4 minutes or until the buttercream is light and fluffy.
Frost the cereal milk cupcakes, then garnish with Cinnamon Toast Crunch cereal pieces!
Notes
These cupcakes will last in the fridge for up to 3 days. However, they taste best when served at room temperature! I like to let them sit at room temperature for about an hour before serving. Wait to top with Cinnamon Toast Crunch until right before serving.Brown the butter: In a small saucepan, melt butter over medium heat. Once melted, stir frequently and watch closely for the formation of brown specs on the bottom of the pan and a nutty aroma. Once you see brown specs, stir for just a few more seconds (it browns super quickly). Remove from the heat and immediately pour into a different bowl to prevent it from burning. Let cool to room temperature. I recommend making the brown butter the night before you make the cupcakes, so that it has time to fully cool to room temperature! Note: For every ½ cup (1 stick or 113g), you'll lose about 1 tablespoon (14g) to evaporation while cooking. So you can either add in an extra 1 tablespoon before browning, or if you're browning big batches, just make up the weight difference in your recipe with regular unsalted butter if needed.