Prep the apples: Peel, core, and finely dice 2 medium apples.
Aim for small pieces (about 1/4 inch) so they fold into the dough easily and bake evenly.
Cook off the moisture: In a small skillet, cook the apples with 1 tablespoon butter, 1 tablespoon brown sugar, 1/2 teaspoon cinnamon, and a squeeze of lemon over medium heat for 4–6 minutes, just until softened and glossy. Cool completely. This step keeps your cookies from turning soggy.
Cream the butter and sugars: In a large bowl, beat 3/4 cup softened unsalted butter with 1/2 cup granulated sugar and 3/4 cup packed light brown sugar until light and fluffy, about 2 minutes.
Add eggs and vanilla: Beat in 1 large egg plus 1 egg yolk and 2 teaspoons vanilla extract until smooth.
The extra yolk gives a richer, chewier cookie.
Whisk dry ingredients: In a separate bowl, whisk 2 cups all-purpose flour, 2 teaspoons cornstarch, 1 teaspoon baking soda, 1/2 teaspoon fine sea salt, 1 1/2 teaspoons cinnamon, and a pinch of nutmeg.
Combine: Add the dry ingredients to the wet and mix on low just until a dough forms. Don’t overmix.
Fold in apples: Gently fold in the cooled apples. If using nuts, add 1/2 cup chopped pecans or walnuts now.
Chill: Cover and refrigerate the dough for at least 45 minutes (up to 24 hours). Chilling is key for thick, chewy cookies that don’t spread too much.
Prepare the caramel: If using soft caramels, cut them into pea-sized pieces.
If using thick caramel sauce, keep it cold so it’s easier to handle.
Preheat and line: Heat oven to 350°F (175°C). Line two baking sheets with parchment paper.
Shape the cookies: Scoop 2-tablespoon balls of dough. Make a small indentation in each ball, tuck a few caramel bits (or 1/2 teaspoon of caramel sauce) inside, and pinch the dough closed to seal. Keep the caramel fully enclosed to prevent leaking.
Bake: Arrange 2 inches apart and bake 10–12 minutes, until edges are set and centers still look slightly soft.
If any caramel peeks out, gently nudge it back with a spoon while warm.
Cool: Let cookies rest on the sheet for 5 minutes, then move to a rack. The centers will finish setting as they cool, staying soft and chewy.
Optional finish: Drizzle a little warm caramel over the cooled cookies and sprinkle with a light pinch of flaky salt for contrast.