In a medium bowl add in the flour, brown sugar, almonds, oats, and salt. Give it a good stir, and then add in the cold butter cubes. Work in butter using finger tips, the mixture should resemble pea sized crumbs.
Keep the mixture in the fridge while making the apple filling.
Apple filling
Preheat oven to 375 degrees and place rack in the middle of the oven.
Toss your apples with lemon juice.
Place the butter in a 10 inch skillet that is oven proof and cook over medium low heat, swirl the pan occasionally. At around 5 minutes mark the butter should be slightly browned and give off a nutty aroma.
Toss in the sugar, the vanilla bean paste, and apples to the pan. Let the apples cook on medium heat till the apples become translucent and tender not mushy. This will take about 10-12 minutes.
Spread the crisp mixture evenly over the apples, bake for 20-25 minutes or till the crisp is bubbly on the sides and brown.