Preheat the oven to 375 degrees F. Add the apples to 9×13 baking dish (or a large skillet) and toss them with the brown sugar, flour, cinnamon and salt. Pour the amaretto over top and toss the apples.
In a bowl, stir the oats, brown sugar, almonds, flour, cinnamon and salt. Add in the vanilla extract and amaretto, then add the butter. Use your hands to incorporate the butter until it is evenly distributed and you have a crumbly mix. Sprinkle it evenly over the apples. Bake the apples for 40 to 45 minutes, until the crisp is golden brown and the juice is bubbly underneath. Remove the dish from the oven and serve the crisp hot with ice cream.