Make the Cookie Dough:

Cream the butter with both sugars using an electric hand mixer for 2–3 minutes until light and fluffy.

Add egg and vanilla, mix until just combined.

In a separate bowl, whisk together flour, salt, baking soda, and cinnamon. Fold into the wet ingredients using a rubber spatula—do not overmix.

Divide the dough into 10 equal balls and place on parchment-lined trays. Create a thumbprint in each.

Chill the dough in the refrigerator for 1 hour.

Make the Apple Pie Filling:

Dice apples and sprinkle with lemon juice to prevent browning.

In a saucepan, melt butter, add sugars and spices, then add apples. Cook over medium heat for 8–10 minutes until softened but not mushy. Let cool to room temperature.

Bake & Assemble:

Preheat oven to 347°F (175°C), no fan.

Bake chilled cookie dough for 15 minutes. Immediately reshape the thumbprint centers after baking.

Let cookies cool on a wire rack.

Fill each with a spoonful of the apple mixture and drizzle with the leftover sauce (apple butter).