Preheat the Oven: Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.
Prepare the Dry Ingredients: In a large bowl, mix together the flour, sugar, and salt.
Warm the Milk: In a separate bowl, gently warm the milk over low heat (it should be warm, not hot).
Mix the Dough: Add the warm milk to the dry ingredients and stir until just combined. Add the egg and vanilla extract and mix until a dough forms.
Incorporate Butter: Gradually fold the cold butter cubes into the dough, ensuring the butter stays cold to create flaky layers.
Let It Rise: Cover the dough and allow it to rise in a warm place for about 1 hour, or until doubled in size.
Roll and Shape: Once the dough has risen, roll it out onto a floured surface into a large rectangle. Cut the dough into triangles.
Add Chocolate Chips: Place chocolate chips in the center of each triangle and roll them up, similar to how you would roll croissants.
Bake the Cookies: Place the rolled dough onto the prepared baking sheet and bake for 15-20 minutes, or until golden brown and crisp.
Cool and Serve: Allow the cookies to cool slightly before serving.