In a skillet over medium heat, sauté 250 grams of finely diced gala apples with 50 grams of dark brown sugar, 1 teaspoon of ground cinnamon, a pinch of salt, and the juice from one small lemon. Cook for about 10 minutes until the apples are tender and caramelized, stirring occasionally. Once done, set them aside to cool and chill in the fridge while you move on to the next steps.

In a medium pot, melt 184 grams of unsalted butter over medium heat until it turns golden brown and develops a nutty aroma, usually about 5-7 minutes. Keep an eye on it to prevent burning, stirring frequently. Once browned, remove the pot from the heat and let the butter cool in the fridge for about 10 minutes until slightly thickened.

In a large mixing bowl, whisk together 250 grams of all-purpose flour, 1 teaspoon of baking soda, 1 teaspoon of cream of tartar, 1.5 teaspoons of ground cinnamon, 1/2 teaspoon of fine sea salt, and 2 teaspoons of cornstarch.

In a separate bowl, whisk the cooled brown butter with 100 grams of dark brown sugar and 100 grams of granulated sugar until well combined. Add in 2 teaspoons of vanilla bean paste, 1 large egg, and 1 egg yolk, stirring until the mixture is smooth. Gently fold in the chilled caramelized apples for an extra burst of flavor in your cookie dough.

Gradually mix the dry ingredient blend into the wet mixture using a spatula or wooden spoon. Stir until just combined, being careful not to overmix. Once blended, cover the dough with plastic wrap and refrigerate for 2-3 hours.

Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper. Scoop out tablespoons of chilled dough and roll them into balls. Toss each ball in a mixture of 66 grams of granulated sugar and 1 teaspoon of ground cinnamon for a sweet cinnamon coating.

Place the baking sheet in the preheated oven and bake the Apple Snickerdoodles for 12-14 minutes or until the edges are golden and the tops are slightly puffy. Remove the sheet from the oven and let the cookies cool on the baking sheet for 5 minutes before transferring them to a cooling rack to cool completely.