Churro Cookies

Instructions

1. Cream together softened butter, brown sugar, and granulated sugar until creamy and pale. Add vanilla, egg, and egg yolk, and mix until combined.
2. In a separate bowl, combine flour, baking soda, cornstarch, and salt. Add this mixture, in two parts, to the bowl of wet ingredients and gently fold until no flour streaks remain. Avoid overmixing.
3. In a bowl, mix granulated sugar and cinnamon. Set aside.
4. Form cookie dough balls, make a hole in the center with your finger, and fill it with Dulce de Leche. Roll the dough into a ball, ensuring the Dulce de Leche is sealed inside. Now, roll each ball in the cinnamon sugar mixture.
5. Place the balls on a baking sheet lined with parchment paper and refrigerate for 24 hours. Chilling is necessary for thick cookies and to prevent the Dulce de Leche from leaking.
6. Preheat the oven to 350°F (180°C). Bake for 15 minutes. Let them cool on the baking sheet before transferring to a wire rack to cool completely.