If using sweetened condensed milk instead of store bought dulce de leche, you can make it ahead of time by removing label and boiling can in water (make sure water is covering can the entire time!) for 4 hours. Set aside and refrigerate until ready for use. Homemade dulce de leche lasts in the fridge up to 2 weeks.

Preheat oven to 375 F. Grease and flour a 9 inch square baking pan.

Line bottom of the pan with sliced apples.

Combine the rest of ingredients except for the whiskey and dulce de leche.

Microwave dulce de leche with 2 tsp water, milk or cream for 30 seconds until warm. Drizzle overtop of apples then add oat-flour mixture.

Drizzle whiskey overtop of crumble, then garnish with whole mini pretzel twists overtop.

Bake in the oven for 30-32 min. Serve with ice cream or whipped cream and enjoy! Will last in the fridge as leftovers up to 7 days - reheats well.