Preheat oven to 350°F and line a muffin pan with cupcake liners.
Whisk the egg yolks and egg white in a large bowl and then mix in softened butter, sour cream and vanilla until combined.
In a separate bowl, combine flour, sugar, brown sugar, baking soda, baking powder, salt and cinnamon. Stir ingredients and then combine with the wet ingredients. Mix together for about one minute, or until smooth.
Pour batter into cupcake liners and bake for 16-20 minutes, or until a tooth pick comes clean. Do not over bake! Allow cupcakes to cool.
Combine cream cheese and butter in a large bowl. Beat with mixers until smooth. Slowly add in powdered sugar and continue to mix. Add in vanilla and cinnamon and continue to mix until smooth and creamy.
In a small bowl, mix together cinnamon and sugar for topping. Then frost cupcakes with cream cheese frosting and sprinkle cinnamon sugar mixture on top.
I used an extra large round tip to frost my churro cupcakes. Check out this easy step-by-step tutorial for extra instructions on how to easily frost a cupcake.
Top each cupcake with a mini churro for an extra special touch.
Can drizzle with caramel sauce (or dulce de leche) before serving.
To make into a cake: This recipe can be made into a cake if preferred. Simply use two 9-inch circle cake pans and bake at 350°F for about 25-30 minutes. Check with a toothpick before removing from the oven.
Mini cupcakes: Add batter to mini cupcake pan and bake at 350°F for 10-15 minutes, or until a toothpick comes out clean.