Preheat oven to 350 degrees, place 24 paper liners in 2 x 12 muffin tins.
Sift the flour, sugar, baking powder, and salt into the bowl of a stand mixer fitted with the whisk attachment. Add butter and 1/2 cup of the milk. Mix on medium speed until smooth, about 4 minutes. Scrape sides of the bowl as needed.
In a separate bowl, blend the eggs, egg whites, remaining 1/2 cup milk, and Rodelle vanilla extract.
Add the egg mixture to the flour mixture in three additions, mixing for 2 minutes after each addition.
Scrap the bowl after each addition.
Filling
Mix all ingredients together in a small bowl.
Icing
Using a mixer, beat all the butter, cream cheese, vanilla extract and vanilla bean seeds until smooth.
Carefully add powdered sugar on low so it can be incorporated into the butter/cream cheese.
Assembly
Spoon 1 1/2 tablespoons of batter into the lined muffin cups, start with 20 cups, if you have enough for 2-4 cupcakes after the assembly of the initial 20, follow directions from beginning.
Sprinkle 1/2 teaspoon of filling onto the batter.
Top off the bottom layer of batter and the filling with another 1 1/2 tablespoons of batter. Smooth the surface with the back of a spoon.
Drag a toothpick through the filled muffin liners to distribute the cinnamon filling.
Sprinkle the tops with 1/2 teaspoon or so of the filling.
Bake for 18-20 minutes, or until toothpick inserted in the center comes out clean.
Cool completely before icing.
Pipe frosting onto cupcakes and garnish with cinnamon stick pieces!
Looking for some other great cupcake recipes? Try our pumpkin cupcakes, double vanilla cupcakes with vanilla buttercream frosting, or for a chocolate fix, try our mocha cupcakes with espresso buttercream!
