Peel, core, and slice the apples into thin wedges.

In a large mixing bowl, combine granulated sugar, brown sugar, cinnamon, nutmeg, cornstarch, and salt; mix well.

Drizzle the lemon juice over the apple slices and toss to coat.

Fold the apple slices into the sugar spice mixture until each piece is coated.

Transfer the mixture to a medium saucepan and cook over medium heat for 5-7 minutes, stirring occasionally.

Reduce heat slightly and simmer for an additional 2-3 minutes until the filling thickens.

Remove from heat and let the filling cool for about 5 minutes.

Use the filling in your pie crust or store in an airtight container in the refrigerator for up to one week.