• Preheat oven to 350 degrees.  Use parchment paper or a silpat mat to line a baking sheet. Cream the butter, granulated sugar and brown sugar in a stand mixer (or by hand) until light and fluffy.
• Mix in egg, egg yolk, lemon juice and vanilla.
• Mix in flour, corn starch, baking soda, baking powder, salt and cinnamon.
• Scoop out about 2-3 tablespoons and roll into a dough ball. Repeat with the rest of the dough to make about 18 dough balls.
• Mix the 1/4 cup granulated sugar and 1/2 tsp cinnamon (Cinnamon Sugar Coating) in a bowl. Roll each cookie dough in the cinnamon sugar mixture and place on the prepared baking sheet. (Save leftover cinnamon sugar for topping at the end) You should have only 6 cookies per cookie sheet and leave about 2 inches in between each cookie. Slightly flatten each cookie dough ball.
• Bake at 350 degrees for 9-10 minutes.
• Allow cookies to cool on the baking sheet for 10 minutes and then transfer to cooling rack.

How to Make Cinnamon Frosting

• Cream butter, powdered sugar, brown sugar, cinnamon, vanilla and 1 tbsp heavy cream until light and fluffy. If frosting is too thick, add a little heavy cream and mix until desired consistency is achieved. If the frosting is too thin, add more powdered sugar.
• Put the frosting in a gallon size Ziploc bag and cut off one corner of the bag. Use the frosting bag to pipe frosting in a spiral on top of the cooled cookies.
• Take the leftover cinnamon sugar mixture that was remained after you rolled the cookie dough balls and add 1 TBSP brown sugar to it and mix. Sprinkle on top of each frosted cookie.